This is the correct answer, full stop. Every other factor is peanuts in comparison. The sheer magnitude of our housing shortage is astonishing: Pre-pandemic, there was something like a ~5 million home deficit. Post-pandemic it grew to ~7 million. This deficit is likely even bigger today.

It's simple supply & demand. We can't reduce demand -- people need shelter. The solution is providing supply. No amount of fiddling with interest rates, corporate real estate investment, or whatever else, will alleviate the housing crisis. (# of houses available) / (# of needy families) << 1. Fix the ratio, or live with the crisis. Everything else is lipstick on a pig.