eh, a modern apartment built with modern noise-dampening standofs on the drywall (something like "resilient channel" - there are several technologies, but the idea is to make the attachment between the drywall and the stud absorb vibration) is better at preventing noise from one apartment to another than older mobile homes are.

it's not expensive, either.

https://www.google.com/shopping/product/1727307288755176845?...

of course, I've never installed the stuff (I've heard stories, though) so I don't know what it does to labor costs.