The reason is that for most homeowners their home equity is the majority of their savings, and homeowners vote in higher proportion than renters (on average). Any politician that allows home values to fall too much will be facing the end of their career.
Under these conditions the only way housing will fall in a lasting way is if something so terrible happens to the economy that... well... you'll have bigger problems than housing.
Housing is fundamentally broken and very hard to fix due to vested interests all over the place. "Housing cannot simultaneously be affordable and a good investment," and we've clearly decided that housing is a financial instrument first and a place to live second.
There is one way out of the housing price trap: telework plus ubiquitous broadband via things like 5G and Starlink. That could allow people to escape the housing trap by locating away from price hotspots. If you simply must live in a big city this won't work for you, but keep in mind that you could always live somewhere more rural and visit big cities any time you please.