The transition to Civ 6 has been arduous, in contrast with 5 which was very streamlined and although it was much more simplified, it still retained a good degree of depth. It wasn't until Gathering Storm that I've finally started to enjoy 6, I still however miss certain mechanics in 5 which were implemented perfectly such as the Ideology system. My point being that I'm still not totally convinced with 6, although the early game is incredible, the mid-late game usually tends to become overwhelming. This leads into my first suggestion;
- We need a solution for wide-empire management. On the one hand I think it's already a criticism that playing tall isn't viable, and by playing wide you always escalate the empire into micromanagement hell. Civ 5 handled this perfectly with the Annex system, essentially allowing you to maintain a core of your empire with the occupied cities running automated yet less efficient. You could gradually annex these cities into your empire via courthouses with happiness acting as a sort of buffer, and it's a much more realistic system, similar in a way to Europa Universalis. Civ 6 on the other hand has no such system, Amenities regulate how fast you can expand but there's otherwise no drawback for expanding, so once amenities become abundant you find yourself with whole continents full of cities, micromanaging individual districts and build orders as well as tile improvements, etc, for every single city. We either need the annex system back or some new system, because it just doesn't work as it is.
- There's just too much micromanagement and certain system aren't very clear, and it actually seems to be getting worse with every expansion. The game has become convoluted with so many systems so that every turn becomes a slog to work through each one as you constantly try to keep on top of everything. The culture victory screen is a complete nightmare, with tourism acting as this kind of vague resource that you're supposed to mindlessly accumulate but not expected to actually understand. Also resource management isn't very clear, it's difficult to work out which resources you have, or at least I haven't found good way. Even just simple things are missing such as the option to set faith purchases to run automatically, so now it's yet another thing you need to micromanage, great... Unfortunately it appears like it may be too late to fix these issues as the systems are already fully designed, but I would suggest that at least a few of the systems could do with a little optimising.
- The policy screen is just too complicated, there are so many policy cards that accumulate through the game that it becomes a chore to sort through constantly, it also doesn't seem right that you can change your government policies so regularly. It's quite a stark contrast to Civ 5 which made policies a permanent choice until ideology which allowed you to change at the cost of your new found policies. Civ 6 should implement some similar ideas, I think that certain policies should only be available for your chosen governing type, which would already clear the board of policy cards drastically, and there should be some sort of significant drawback to switching government types.
So ultimately it's micromanagement ruining the mid-late game and the lack of viability for tall empires, other then that it's actually a pretty well made game.