I think I am a millenial and while I definitely know people who do own homes (I am trying to get one myself soon admittedly) I don't think they are even close to the majority. Every one of those lives in a more rural or semi-rural area. If you live in a major city, especially in the western world, good luck.

The basement part is even weirder. Some areas you just can't practically have basements. Whether due to the building codes of that area, the risk of flooding, or just culturally it not being a thing.