This alone should be a big red alert to realize something is wrong. The fact that there is little reason to grow Cities past Antiquity. Cities dont grow, which break immersion
ABout what is a sandbox experience, i never thought i would have to define sandbox, and i think the fact that people are asking for definitions to basic stuff saus a lot. And yes, restrictions and sandbox are opposite, because the point of a sandbox game is to allow the player to do whatever they want
Having predetermine objetives for example goes against the sandbox concept
In terms of unpacking, the 2 buildings per tile restriction also goes against the sandbox concept, and you can call it depth as much as you want, but the reality is that the player gets less freedom
I dont know if my point is popular or not, i am a boomer after all so maybe it isnt. Current gaming has objetives that are different to what we had back in the day and its ok, its natural for that to happen
I played the most Civ3, for almost 20 years. Most games I won by space ship, with the second-most-frequent VC being domination.
On lower difficulties, yes, they player could "do whatever they want" and win whichever way they want. However, if one wanted to win by single-city-culture (something I have not achieved), one needed to use focused tactics and strategies. Winning by UN vote took planning, not sandboxing. At higher difficulties, one needed to expand rapidly and build a military to fend off the aggressive AI. Peacefully expanding, just doing whatever wanted risks losing the game at levels above Emperor. Yes, you could build (almost) every building in every city. Yes, you could found (and conquer) 50 cities or more.
I played some Civ4 BTS. That game had much more aggressive AI, more likely to become a runaway, even at Prince/Regent difficulty. The sandbox aspect was present -- build as many cities as you want, build cottages or farms -- but one could also tank the economy by expanding too fast.
While both of those games had lots of flexibility, both had mechanics which risked losing the game if you just "did whatever you wanted."
I played a lot less Civ5, because I couldn't build cities or conquer them the way I wanted to. The global happiness mechanic was a buzz kill for me.
I enjoyed Civ6 because I could found and conquer as many cities as I wished. Yes, each city had a bigger tile footprint, but I was free to choose which districts to put down, and how many.
I still prefer winning by spaceship, but Civ6 requires many more turns to get to all of the necessary techs than did Civ3 or Civ4. I could "do whatever I want", build an empire of 20+ cities, but unless I focused on conquering capitals, I wouldn't stumble into a victory. I needed to build the Statue of Liberty, to ensure that an AI didn't snipe the diplo victory.
Unpacking the cities in Civ7 has more constraints on what goes where. I agree that's less sandbox than my trusty ol' Civ3. But I don't have rose-colored glasses for Civ3; I still needed to work to win.