The reason economists get so excited about abstract issues of market efficiency is because if supply and demand don't balance naturally there will either be too much or not enough of something (effectively). Introducing rent controls will push the market towards the not-enough end of the spectrum and shortages will get worse.
> The unregulated market has never and will never provide affordable housing to all on its own.
That is a huge claim. If people could use their land as they like there probably wouldn't be a housing shortage. Developers make large fortunes out of install dense blocks of apartments; and doing that isn't going to make housing more expensive.