You are correct. Though I think the belief that realtors drive the prices up is a common misconception from the basic intuition that realtors want to push the prices up since they get paid by percentage. It's an easy mistake to make.
I think the real cause for the housing crisis in the USA is simple: contractors stopped building houses after the last housing market crash (which was clearly caused by overdevelopment). They allowed the supply to naturally shift, so now demand outstrips supply and that is driving prices up. BUT, it is not driving sales up, because the prices are now so high that most people can't afford them. So that's why high-priced houses are sitting on the market.
I read, right here on slashdot, some time ago, that some states have made efforts at getting more houses built, but the only houses any contractors are interested in building are high-end luxury homes since those have a higher profit margin. They will sit unbought as well, since they will still be out of most buyer's price ranges.
I don't know the latest on "affordable housing" efforts, though I am aware of companies like "Boxabl" making affordable-yet-modern tiny houses to try to hit that market. I just don't know how widely-deployed these are, or are set to be in the near future.
This problem will sort itself out if we just wait long enough. With plummeting birth rates, demand will fall to the point where it no longer outstrips supply. That will force prices down, though it will clearly come with other economic problems.
Building more houses, especially low-end houses, is the fastest way to address the housing crisis, though even that will have an overall price-lowering effect which a lot of current home-owners clearly don't want (and they are a significant voting demographic, so their collective pressure against building more houses is non-trivial).