I've been saying it since well before release, but it's very obvious that Civ VII was made with DLC in mind instead of fun or being a good game. Why is it symmetrically balanced? Because it's a lot easier and faster to churn out civilizations if you do that thanks to the ease of balancing to a model. Why is there civ switching? Because you don't have to worry about things like "is this midgame power bump strong enough to overcome the feels bad of having nothing special in the early game" if there is no early/mid/late game to worry about for a civ. Why are you switching civilizations instead of leaders despite the latter clearly making more narrative and historical sense*? Because civilizations are a palette swap but leaders require new models.
You indirectly touched on this, but Civ VII is also a pretty good case study into why this "new school" of game development where you do "data driven balancing" and strongly listen to your fanbase despite your fanbase being lazy and knowing nothing about game development/balance makes terrible games. Gates of All nations is nerfed because the data says people build it a bunch while ignoring that there are other ways to make people build it less besides nerfing and that an equally likely reason it's built a lot is because the game makes you build a bunch of wonders in that age so players are going to build whatever the AI doesn't prioritize regardless of how good it is. Similarly, the second you make it clear to your playerbase that balance changes will be coming regularly, they stop trying to innovate and instead move to whining on social media. Sure, Street Fighter 4 had major meta changes several years after mainstream tournament support stopped to the point that every tier list you can find on the internet is stone cold wrong, but sure, clearly Gate of All Nations is overpowered. As for the listening to your fanbase part, basically everything people point to as disliking about age changes you can point to a large portion of the fanbase begging for. People told you they wanted civs to have something strong in every part of the game. People told you they wanted to have more exploration. People told you they wanted games to not snowball (which itself just an AI problem, but that's another story). Firaxis delievered a mechanic that does all of that, and it's panned for reasons you went into. It being panned was predictable for the reasons you went into, but they still did it.
I also strongly disagree with AI being "fiendishly difficult". The series has simply not invested into it at all since Civ IV. That's why the AI has been bad and why Civ IV is the last game that was actually challenging to somebody who has played strategy games before. I'm not going to sit here and pretend it's easy to make a good 4X AI, but basically everyone I can think of has a fanmod that creates a competent AI that doesn't resort to cheese. If fans not even in the industry can pull it off, there's no reason why Principal developers should be unable to. Of course this is a rhetorical question and I know the real reason why it's so consistently bad is because AI is necessarily the last core mechanic you finish in a strategy game, so the minimum viable product always prevails. While there will always be the purists who will accept nothing short of "elo adjusted" stockfish, I don't think most people actually have problems with, say, Civ IV giving the AI supremely cheap unit upgrades and a tech bonus to make up for the fact that it's coded to stop research and upgrade the entire army every military tech researched in order to prevent timing cheeses where you roll over the ridiculously ahead AI that can build cavalry with knights because their cities are still defended by archers.
*I'm sure people will take offense to that, but plenty of civilizations have not meaningfully fallen, and of the ones who did, it was usually because of things already modeled by the game. AKA they got conquered and their conquerors had more in common with the Assyrians than the Romans.
It's worth pointing out that this only started with Civ 5. Civ 1-2 didn't have unique civ strengths and weaknesses. 3-4 only had generic traits and UUs. The asymmetrical balance was still there in 1-4 through things like wonders though. I think that's important though because in Civ 2, you'd feel like you just broke the game if you built Leonardo's Workshop. In Civ 6 these types of moments come when your civ has its dominant era. In Civ 7, when is that moment?
Civ 3 had trait unique starting techs and Civ 4 made it civ specific starting techs. This radically changed the game in practice and is absolutely meaningful asymmetric design.
It really feels like the devs don't want players to play with history...
What's especially frustrating is that we know Firaxis knows this because they made sure that China-China-China was possible to appease the Chinese market, but the rest of us? Nah, you'll get the slop and you'll like it.
Do you believe that there should be any limit to how many units should be able to occupy a tile?
Why should there be? Normandy is the only battle in history I'm aware of where not having enough space to put all your equipment and men in was a real consideration, and while I'm personally pretty over litigating 1UPT with the new age civ players (especially because stacking is never coming back and even Soren Johnson has seemingly abandoned it), supporting it causes a lot of strategy and tactical problems. Because like they said, the system marries strategy and tactics which are at odds with each other. Like Old World doesn't allow free settlement because they wanted 1UPT combat to feel better than civ, and that was a necessary cut to do it.
Civ 5-7 were made by the TLDR generation for the TLDR generation. That's the problem and it's a shame.
I'm young enough to be in that generation, and that's a good way to put it. In the grand scheme of things this is minor, but in Civ 7 the leaders in the open scream cough, grunt, and generally make noises at you to hurry up and play if you try to read the leader and civ bonuses before you start the game. Apparently you're supposed to just blindly click things in civ games now. Thinking about your macrostrategy early on is not allowed. It really is depressing to think how far the series has fallen on this front. Civ VI still had enough meat on the bone that I enjoyed it, but it was very much so, to use this post's nomenclature, confusing wide complexity with depth. Civ VI was a much less deep game than 2, 3, 4, and SMAC. Civ V and VII aren't deep at all.
There were plenty of issues with the combat in Civ 4, or another way to put it is -there was a lot of room for improvement of the systems for the next iteration. But that would have been work and might have required some creativity.
The designers have developed their excuses. Players don't really want a good AI. It is impossible to create a good AI. Players don't want micromanagement. Etcetera. None of it is really true. These are just excuses to avoid work. Slap a coat of paint on it (graphics and some voice acting) and call it soup. Or slop really and the public just laps it up. Well, the jig seems to be up.
I would argue there were only three real problems with Civ 4 combat.
1. It was too complex for the median player to understand which has somehow managed to domino its way to doing a ton of damage to the genre as a whole.
2. More care needed to be made to smooth out the combat result distributions. As it stands there are really weird breakpoints that resulted in three.
3. Unit balance was really poor. You were usually only not using mounted units because you didn't have horses or needed to use draft to get an army online in time between them being so generically strong numbers wise AND having huge tactical edge further exacerbating that numbers edge. Some counter units like spearmen and pikemen didn't actually function as counter units because of this generally poor balance/two. Elephants are as strong as units an era above them for confusing reasons.
So, if we think of Civ 7 it's not a Civ-sized game, it's three mini civ games. In terms of quantity, that might equal a full civ game, but you only ever play in the context of this very contrived three tiered progression leading to a hard age end.
Maybe it'd be different if I didn't bounce off so fast, but I don't agree with this at all. I could play 6-7 civ IV games in the time it took me to do my first Civ 7 game. The game is really, really long. It's just not very good, the decisions are uninteresting, and the UI makes it actively hard to play.