You didn't mention your son was married lol.
I don't know about "shouldn't." There is no God-given right for every single human alive to own a home in their 20's. It's a lot harder for our kids than it was for us, but it's still WAY easier for them than 95% of the world.
I don't know a whole lot of illegal immigrants who are buying $250k homes. I think it's more that people from expensive areas are finally realizing those expensive areas aren't worth it, and they're taking their massive windfalls from selling their homes and moving to lower cost areas, which drives the cost of living up there because they're brining their wealth with them. Prices go up any time you raise the money supply, and the local money supply goes up when people with lots of cash move to areas with less cash.