When it comes to Civ 7's graphics, what I have seen of it so far, I think it looks pretty good overall. I understand that people have different preferences. I grew up with crisp pixel graphics on systems like the Amiga 500, many games which looked a bit like this:
I guess this had an impact on my tastes. Later there were a lot of 3D games, but the games which were most pleasing to look at for me, was often the crisper, 2D, pixel art style. Like Patrician 3:
That game came out in 2002, but I still think it looks stunning.
Getting back to Civilization and its more recent competitors, I think the ones which are most visually noteworthy, are probably Humankind and Ara: History Untold. Just as a reminder, Humankind looks like this:
I think it is quite pretty, but it has a few drawbacks. For one thing, this map view disappears when you zoom out a bit, and is replaced by a rather dreary, I guess "strategic" view, full of little numbers, symbols and text. For another, due to the way cities and regions work, there is extreme urban sprawl, and almost the entire map will quickly become plastered with districts. It ends up looking very visually busy to me. I'm not saying it's a bad looking game, but in my opinion, it doesn't quite live up to the promo screenshots in practice.
As for Ara, it is a game which I thought looked rather ugly in the early promo screenshots. With the third alpha however, my opinion changed. I'm not allowed to post screenshots from my own gameplay, and the promo screenshots mostly don't quite do it justice, but I grabbed some screens from a trailer. There is some compression, but they give an idea of how it looks:
It has kind of a detailed, somewhat realistic, "city builder" aesthetic, which I personally really like. It also helps that the map is full of life, with people and animals walking around. For me, this is probably going to be the main competitor to Civ 7, both in terms of visuals and gameplay.
Getting back to Civ 7, it seems they are going for a similar style to Civ 6, but clearly modernised and improved. The map looks pretty good...a bit sparse, but not bad. Where it shines for me, is the buildings and improvements. Screenshots like these are beautiful for me:
Of course,this is zoomed in and angled in a way that doesn't reflect normal gameplay, so the game will not look *this* good all the time. But it's still impressive to me.