> ...most people don't care about loud sound levels anymore.
It's probably less this and more (at least in the US) that it's very, very, very hard to find "multi-family" housing that's not soul-crushingly substandard [0], so at some point you just give up and try to do a reasonably good job of balancing "living your damn life" with "not making so much noise as to be enormously obnoxious too often".
[0] It might be true that very few USians have ever lived in a place with actually adequate acoustic insulation... so very few folks even would think to look for it.
It's probably less this and more (at least in the US) that it's very, very, very hard to find "multi-family" housing that's not soul-crushingly substandard [0], so at some point you just give up and try to do a reasonably good job of balancing "living your damn life" with "not making so much noise as to be enormously obnoxious too often".
[0] It might be true that very few USians have ever lived in a place with actually adequate acoustic insulation... so very few folks even would think to look for it.