The use of masonry is limited by the requirements to withstand severe earthquakes, which are endemic throughout much of the US. I’ve lived in apartments that we

The use of masonry is limited by the requirements to withstand severe earthquakes, which are endemic throughout much of the US. I’ve lived in apartments that were effectively soundproof but those were legacy buildings where the interior concrete and masonry walls were not engineered to withstand earthquakes. It is pretty expensive to build apartments that are soundproof and can survive a magnitude 8+ earthquake. You can’t just throw building mass at the problem as is so common in Europe. Buildings need to have a lot of elastic flex to them.