> whereas my friend's 20-year-old house has screws or nails starting to pop out of the drywall everywhere.

This is a drywall installation issue, though, like you said. Lath and plaster can have the same exact issue with popping. And unlike drywall, lath and plaster has issues with cracking especially if done poorly.

Regarding acoustics, you can easily improve acoustic performance of drywall in many ways. Double layering, acoustic sealing caulk, rockwall in walls, etc. You don’t need plaster to do that.

The only reason I can think that lath and plaster would be superior now is that the floor for how poorly it is done is likely lower, purely because it’s a bit of a lost art.

>you can easily improve acoustic performance of drywall in many ways. Double layering, acoustic sealing caulk, rockwall in walls, etc.

There's a principle-agent problem here. It is hard for a home buyer to verify claims of the existence of the things you list whereas lath and plaster is easy for a non-professional to learn to recognize. Lath and plaster also is better at forming curved surfaces. (I'm a particular fan of coved ceilings.)