Districts, wonders on the map, Builder charges, unique Great People, and maximally asymmetric civilization designs are, IMO, Civ6's best features that I want to return. It's a little thing, but walls contributing to tourism is another feature I really like. I also love unique improvements and districts--I think every civ should have some feature(s) that make my territory look like my territory. In fact, I think every civ should ideally have a couple different things making their cities look unique (including Civ6's greater attention to unique architecture--a trait that needs to extend to districts IMO).
There are also some things that Civ6 did well or well enough that I would not necessarily want to return or at least would want fine-tuned before returning. I like Traders building roads, but I think the system needs some adjustment. Unique City-States is a great feature, but I'd like to see it replaced with more civ-like minor factions, more akin to those you'd find in an Amplitude game like Endless Space 2 or even the dreary Humankind. The art style of Civ6 is great--much better than the gaping eyesore that is Civ5--but that doesn't mean I don't want to see a new approach for Civ7; leaders in particular could use some stronger art direction. Era themes were a great idea but lead to a lot of repeated music; I'd prefer an approach that leads to more ambient music. Disasters are a feature I love, but things like tornadoes are just too ephemeral and local to be included. Keep the risk/reward factor, but tone down some of the random wantonness (I'm particularly looking at tornadoes and hurricanes here). I would also love to see some of Civ4's random events return as I think they're a great addition to the narrative; I was hoping for them in R+F or GS.
There are also some things that Civ6 did well or well enough that I would not necessarily want to return or at least would want fine-tuned before returning. I like Traders building roads, but I think the system needs some adjustment. Unique City-States is a great feature, but I'd like to see it replaced with more civ-like minor factions, more akin to those you'd find in an Amplitude game like Endless Space 2 or even the dreary Humankind. The art style of Civ6 is great--much better than the gaping eyesore that is Civ5--but that doesn't mean I don't want to see a new approach for Civ7; leaders in particular could use some stronger art direction. Era themes were a great idea but lead to a lot of repeated music; I'd prefer an approach that leads to more ambient music. Disasters are a feature I love, but things like tornadoes are just too ephemeral and local to be included. Keep the risk/reward factor, but tone down some of the random wantonness (I'm particularly looking at tornadoes and hurricanes here). I would also love to see some of Civ4's random events return as I think they're a great addition to the narrative; I was hoping for them in R+F or GS.