I love the game civ6, that's why the problems with it make me troubled and I want to suggest improvements. I've played through multiple playthroughs and here are some issues that stand out to me.
TLDR: Civ6's gameplay forces you to play in a very imperialist, chauvinistic, racist, and religious way to win.
Problsms
'Barbarians' (indigenous or native people, obviously stereotyped as always warlike), the tech tree that forces you to discover things in the way the Europeans discovered them, not just making you unlock actually necessary technologies before you unlock new ones, even more so with the civic tree as any policy or government can be developed in isolation, it doesn't need the preceding civ6 ones, also you can't have a democracy from the beginning if you want what's best for your people. You have to conquer other continents displacing or killing the natives, and the way it frames certain governments such as communism is disingenuous when they're really describing authoritarianism, and making that misunderstanding more widespread.
My suggested solutions/improvements
Abolish the civic tree. Let you establish any government or any policy ( you can still have policy slots but it's the same across all governments) at any time without culture cost. Governments could affect things like the happiness and productivity of your people, but not more than that. Rename 'barbarians' to natives or indigenous people and create more peaceful options for interacting with them, don't make them aggressive by default. Encourage cooperation with civilisations on other continents (such as lasting trade agreements that you don't have to renew every 30 turns) rather than encouraging settling everywhere on the map. Allow individual cities to get upgrades that allows producing multiple things at once rather than the only way to do so being creating multiple cities. Allow agnosticism or atheism as a 'religion' option and rename religion to 'philosophy' or 'ideology' or something like that. Having real historical cultures and leaders on a generated world doesn't really make sense so there should be fictional or generated civilisations and leaders as options too.
I don't mind if they keep the victory conditions they've got, scientific, religious (although ideological is a better term), military, although not cultural. If people want to play as murderous colonial maniacs they should be allowed to, they just shouldn't be forced into it and should have more peaceful options to play. The scientific victory should be collaborative, with multiple civilisations working together to advance scientific knowledge and improve human conditions (although the current goal of space travel is overly simplistic). Convincing the world of your ideology isn't a bad measure for success either, and conquering the world military is a kind of success, if not a very moral one. Culture victory is just a thinly veiled way of saying that only European culture is good and the way of proving your culture is best is attracting tourists, which is again overly simplistic.