I don’t think it’s that simple in a sense. You risk crashing the housing market which will leave a lot of people that “just barely made it” into the housing market far worse off if you just rapidly mass-build housing.
There also just aren’t that many builders/contractors that do good work available so you run the risk of building a lot of housing that’s in a state of disrepair soon after construction/never built properly. There are plenty of housing inspectors on youtube speaking out about housing developments and how ridiculously bad a lot of the modern builders are.
You also need to find the land to build on in a time when land conservation is increasingly recognized as important/there’s little public land left. That means buying up even more (likely) good farm land.
You can start buying people out of their inner city neighborhoods in disrepair and start revitalizing them, but that’s gentrification that often leaves the people that were living in those homes worse off. Where I am in Akron there are plenty of houses, just lots of them folks don’t really want to live in them (they’re in disrepair in “high” crime areas) or they’re being rented for absurd prices. I think revitalizing these neighborhoods and forcing a cap on rental properties is the most promising, but it needs paired with a general economic support system for those already living in the neighborhood.