It's not just Civ VI that doesn't live up to the expectations of Players who played and enjoyed previous iterartions of the Series, but nowadays most 4X Games in general. In the Past, 4X Strategy Games used to be more engaging but without too much mechanisms for the Player to feel too much (and enough for the AI to handle everything right). A perfect example is Master of Orion II, which was built on the first Game (and Master of Magic) but included more of everything, which isn't always good. it felt too much. The Game was still good, but nonetheless the first Game was much more liked by the Fans than the second one. And don't mention MoO III to the Series' Fanbase, they will mostl likely ban you immediately
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Most of the 4X Genre Games nowadays try to implement a lot of things at once, mostly to try to beat their predecessors or competitors with new features. Which make those games bloated but at the same time with not much deepness. They also focus on making the game playable by as many Players as possible, to attract new Players, even players that aren't 4X Genre fans, casual Players, Adults AND Kids, lately even mobile players ...etc, which make the Game Mechanisms Simple enough for those Players to understand and enjoy, but at the Cost of the 4X Strategy Fanatics who like more deepness to the gameplay.
Yet, some Games do a really good Job on some of that, like
@Kwami 's example of CK3.
I don't think that Games, that have as many Players as possible under their Radar, should change their Mechanisms/Playstyle accordingly. The programming Options Nowadays are nearly Endless, and much better than they used to be in the 90', where 4X Games used to only please the players of this Genre (successfully). What I'm thinking about is Automated Stuff In-game. Distant Worlds Universe offers a lot of automation options to manage nearly every aspect of the Game, which makes even it's larger maps easy managable.
Now Imagine Civ adopting this Systeme into the Game. I saw a lot of Players not liking/enjoying the battle/combat aspect of the Game, and others disliking The Micromanagement of Governors, or bothering about Trade Routs which shouldn't concern the Leader directly but the Citizens. If things could be automated, it would solve three things at the same time, managing things that players don't wanna deal with (don't care about relegion? keep it automated), the Micromanagement of some things (Some People enjoy micromanaging their Cities with tall play, others would rather go wide but have tactical Combat/Battles), and New Players could easily concentrate on one/some thing(s) at a Time, while everything else is automated.