This is why you need a two prong approach: city-led redevelopment or redevelopment incentives on top of rent stabilization. Boston is not rapidly growing new housing relative to the number of people who are trying to live there. The median rent price per capita of the Boston metro is much, much higher than NY metro, nearly 4x in fact.[1] Boston should not be as expensive as New York, when the latter has rent stabilization (and even some old apartments still under rent control) and the former does not.

> I don't understand how the owners remain solvent.

I think that tells you everything you need to know about who's renting them out.

[1]: https://constructioncoverage.com/research/cities-with-the-mo...