To me, we've had quite a few games this gen that were head-and-shoulders above anything the PS3 or 360 could do (The Order: 1886, Metro Exodus, and Death Stranding immediately come to mind). It's been quite the gen for visuals.
That said, you haven't seen anything yet.
Oh there's definitely been games this gen that look much better than anything PS3/360 could do, absolutely, even on Switch there's games that clearly exceed last gen graphically. The perceptible leap just wasn't as impactful as prior generational gaps to me personally. Perhaps next gen the difference will be more pronounced to my subjective perception.
Bet with Liquidlaser: I say PS5 and Xbox Series will sell more than 56 million combined by the end of 2023.