Hollow Knight, Crosscode, Hades, Dead Cells, Signalis, Dusk, Outer Wilds, Underrail, and more are all great examples of relatively modern games that kill it in the graphical department without using anything fancy.

Edit, because this is fun: Boltgun, Sea of Stars, the Bloodborne PS1 demake, Tunic, and more.

Minecraft shaders look great though, especially the rtx one for bedrock. If it was more open source, I'm sure ray tracing would be great to implement into shaders.

Celeste still has really nice lighting in places, imo, but you are right, it all just comes from good colour choice and artistic skill, not some premade graphics option that they flipped on.