This opinion sets up corporate consolidation as the cause of all issue in the US. I don't think it makes sense for that to be the null hypothesis that needs to be disproven.

For this specific issue, homebuilding, and construction in general, are very regional businesses. There just aren't a few giant homebuilders controlling the industry across the nation.

There are certainly some antitrust issues with rentals, but they don't seem to be nearly as widespread as the housing issue in general.

I don't think the punching down vs up lense is a particularly effective way to analyz this issue. Nor do I think its easy to figure out who's "down" and who's "up".