Usually YIMBYs (the annoying neolib kind) mean no parking, no transit, no regulations on housing, let developers do whatever and let it rip. Before regulations came in, there didn't use to be clean air standards or light or fire considerations, nor protections like ADA. They want slums for the poors and nice condos for them with no parking and no transit ("hire a cab ya bum").

The socialist resolution to the contradiction of housing is to decommodify it entirely and provision housing based on need instead of profit. Keeping it as a market commodity means slums or this half fucked thing we have now where there's tons of houses out there that are empty but people are not allowed to live in them because they aren't profitable.

Yes, we want to build - we need to build - denser and dignified housing for all, that can also be energy efficient and built out of carbon neutral/negative materials and techniques. Yes, it'll probably be in some former rich fucks backyard that he was hoarding.