There's a huge gap there where building housing would still be entirely profitable, if only we didn't have the self-inflicted wound of the permitting and zoning process in most major US being extremely slow and expensive.
For example, new row houses are explicitly or implicitly illegal in many cities (and thus all the old ones are extremely expensive), despite being both immensely popular for urban families and cheap to build in bulk.
Row houses are an interesting solution as long as there is a 30 dB or greater sound attenuation between apartments and a 90-minute firewall between them. Row housing is also interesting because it allows for the inclusion of a garage and charging infrastructure beneath the house, as well as a space to store home-scale batteries charged by your rooftop solar panels.
And just because you mind living with noise doesn't mean everyone does. Why should we outright ban places like that if there are people who might not be able to afford something better, or don't care and would like to save some money?
Like, your entire comment is part of the goddamn problem. Don't legislate your preferences.
Of course an outright ban is pretty extreme, but alternatives to overcoming this information asymmetry are not straightforward. Ideally: compulsory testing and disclosure, if it could be done.
The original start of this whole thread included a list of things the author wanted to see happen, which falls into the same category as legislating preferences, or, as I see it, a baseline that is higher than what we have today.
I'd deal with having to hear the neighbors fighting every once in a while vs never having to hear some small-penised individual revving his stupid engine ever again. One way of getting closer to that is building more dense housing cheaper. If we're talking about urban noise floors, start at the real fucking problem.