I feel like this is more an issue with cheap construction (and what people will pay for) than anything else. I've stayed in people's apartments in the UK where

I feel like this is more an issue with cheap construction (and what people will pay for) than anything else. I've stayed in people's apartments in the UK where the light fittings rattle if upstairs is running a wash. These flats aren't cheap either, in the South East they're eye-wateringly expensive for the build quality (eg 250k for an "entry" two bed flat in a commuter town). Having lived up north for a few years in a detached house with a garden, it would be extremely difficult to go back to a flat (especially one in London that costs double the price for half the space). There is a massive supermarket five minutes down the road from our house and town is 15 mins drive. These places absolutely exist for reasonable prices. When/if we finally buy, we're looking at a rural, passive self-build where we can work remotely. The cost is about the same as a town house these days. There isn't any technical reason why you couldn't put in proper isolation between floors or walls, aside from the fact it would slow down construction and be expensive. Proper insulation (both acoustic and thermal) also makes rooms smaller in a given footprint which is an issue for marketing.