We're talking about a layman. Not to mention that different genres have different quality of AI music.
I would easily recognize AI generated orchestra, while I can bet a lot of money that AI generated EDM is hard to distinguish from something created in a DAW
This is a musicaly illterate position. You only find the instruments passable because you're not familiar enough with music. You hear vocals and because you have a decent understanding of what a human should sound like you can tell how bad it sounds. Anyone with a musical ear hears the same thing of the horrible AI generated instrumentals.