I feel this was largely predictable, and for one reason I almost never see mentioned - the millennial generation just being larger than the one before or after. Millennials are noted as being the largest generation since the boomers, and their coming of age as far as prime home-buying time coincided with the collapse of housing construction post-2008.

There's other things at fault, of course - zoning, economy, interest rates, etc. etc., but the current stress on the housing market lines up pretty nicely 80s-born millennials (particularly those that graduated into the great recession) finally hitting their stride and having the wealth to move out/stop renting/have kids, after most of a decade of that being suppressed.

I'd expect this to continue being a problem for the rest of the decade and peter off in the 30s - it feels like governments are taking action (years late as usual, but better than not); movements like YIMBY have matured, boomers are hitting the age where they start to pass, and housing construction has ramped up slowly in the last 8-10 years, and millennials will have mostly bought by then, with gen Z being the new, smaller crop of buyers by that point.