Does screen sharing actually have reasonable resolution and latency befitting of the Apple Studio Monitor?

On LAN (no internet, wired), it's quite decent. With e.g. Parsec, it's quite high image quality, low single digit latency, so quite usable.

Not really, unfortunately, even on wired LAN latency is noticeable, but I'm just editing code so it's at least doable. Resolution isn't bad. I wouldn't recommend it for graphic work or gaming. The only benefit that isn't degraded is the nanotexture on the studio montor, haha.