It’s better audio than what’s in the monitor (and the non-Minis are way better.). There will be lag from AirPlay; macOS corrects for most of it but realtime audio (games, etc.) will be unnoticeable.
I would guess you’d be better off with more directional bookshelf speakers/monitors unless you want the audio from the computer desk to fill a room while you’re not sitting down.
Pair of HomePod minis (either side of the Studio Display)
Those are in increasing order of quality. Most computer audio goes via the Studio Display which is more than fine for most things. When I run Portal, I use AirFoil to AirPlay its audio to the HomePods, or sometimes if I want music I just bring up Music on my phone and ask it to control the HomePods directly.
Music is fine on the Studio Display, but better on the HomePods and I like the ability to simply tap the top of one to quickly pause if a phone call comes in or I just want to leave the room and not miss anything.
I tried AirPlaying from Mac Music to the HomePods, and also using Mac Music to control the HomePods directly… let’s just say .