Bill Gates owns 275,000 acres in the USA. I doubt he's even gazed upon half of it. The billionaires aren't buying homes to live in like us proles, they're buying lots of finite land and water rights and such.

That is about .01% of the US land area, and I’m guessing it’s not downtown in major cities or other places that people want to live. It’s probably mostly undeveloped wilderness for conservation, right? That has zero effect on home prices.

There is no shortage of land in the US. There are huge, huge empty spaces. There is only a shortage of housing in places where people want to live because local governments won’t let anyone build new housing.

Edit: Looked this up, and Bill Gates owns farmland, which is producing food, so this also wouldn't be available for people to live on anyway.