I wish the "it's all supply side" meme would go away. With Western countries importing millions upon millions of people from other countries--and sometimes, implicitly importing them with wide-open borders like the US--the demand side is at least as much at fault. Western country birth rates are already near replacement levels; we shouldn't have to be building more housing in the first place!
The US is below replacement rate on 3rd generation+ families, and would experience an aging crisis like Japan if it were not for immigration. You're 'wide open borders' statement is just a dog whistle.
As someone currently sponsoring my immigrant spouse, I can first-hand tell you: the US immigration process is probably a lot more complicated, slow, burdensome, and frustrating than you think it is. It's expected to take 18 months and over $2,000 in various fees before my (currently undocumented) spouse will get a green card, and be able to begin working legally in this country.
