>if SROs with regulations could exist

Regulations are why they don't exist. Once you pile on everyone's additions to the bike shed it's an economic non starter.

Yes for a reason, perhaps we got the regulations wrong and they need to be looked at. I don't think its an economic non-starter just a complex issue. SROs existed before precisely because they were economically viable. Ultimately we need to reform zoning (in the US) significantly because it has major issues related to local power having inverted incentives to solving zoning and housing concerns at the state level