We already did this ages ago -- most cities have already made all the changes you are requesting, years or even a decade ago. Your talking points are like 10 years behind the times, housing is already legal in 99% of the US right now. (basically everywhere that isn't SF / Bay Area). And you can see brand new 5+1s all over every city, as proof of it. (so much so, that press even writes about it - https://www.bloomberg.com/news/features/2019-02-13/why-ameri... )
Yes, neighbors complain and complain, and it's easy to focus on them, cause they're loud and annoying. But they don't win -- they complain, and then the investors win anyway, and still get to build almost anything they propose. (I'm in the Midwest, and I can count on one hand the number of times an investor lost a proposal -- they get to develop anything they want 99%+ of the time)
> People are so desperate for some bogeyman to blame. Institutional investors! RealPage! Short Term Rentals!
Well, because those are actual issues, and "NIMBYism" isn't. "NIMBYism" is maybe 2% of the overall housing problem, while private equity, investors, illegal hotels ("Short Term Rentals"), pricing collusion ("RealPage"), and such are, collectively, probably ~50%+ of the problem.
There's dozens of problems at play with crazy-high housing prices. "NIMBYism" doesn't even rank among the top ten of them.