When I can see my nose hairs' hairs in selfies using my Sigma Art lenses on my Z7, I think I'm good.
I also have the 'old' 50 1.8G, and while it is very nice, it does not compare to the new stuff from Sigma and Nikon S/Z. It is great on my F6, as film cannot resolve what the other lenses can offer.
But... if pics matter more than peeping, then the 50 1.8G is still just fine. As are most lenses.