The biggest benefit I've noticed with plaster walls is the soundproofing. There's more layers of much denser material. My walls are 1 inch of plaster with meta

The biggest benefit I've noticed with plaster walls is the soundproofing. There's more layers of much denser material. My walls are 1 inch of plaster with metal lath (vs the typical 1/2 thickness for drywall), on top of traditional wood slat lath, then insulation and studs. Typically if you have construction old enough for lath and plaster walls, they might also have independent studs per side, further isolating sound transfer. It's also less porous and doesn't hold water like drywall, making it quite mold resistant.