Most boarding houses are not code compliant and would not be buildable today. That might have something to do with it.

Which brings us back to

"The 2019 system is that building housing is illegal without very costly and hard to get permits in most non Texas big cities.

If you could just put up housing on land you own and charge however much people will pay for it, this housing crisis would quickly be gone"

Nobody is going to build a flop house as new construction even in, especially in, Texas. Have you been to Austin before? It isn’t much better than Seattle.

A lot of them were just old houses that were unrenovated. They’ve probably been torn down and rebuilt by now. My first place in the U district (1994ish) was a cheap $225/month basement room with shared bathroom and a small kitchenette. The land lady was desperate to keep non-students out so it wouldn’t turn into a flop house.

The kinds of subdivisions that turned large homes into multiple boarding situations is also not code compliant and would require at the very least a conditional use authorization (years and uncertainty) in SF.

It was allowed in Seattle in certain districts (definitely at Greek row). Not sure about now.