That thinking is very location-dependent. Cities and counties across the US vary wildly on the ratio of cost-to-rent to cost-to-own, and that number is sometimes less than and sometimes greater than 1, depending on where you are.
A big problem with renting is the capriciousness of the rental market in many places, which you can't solve with "basic math". That plus the availability of the 30-year fixed-rate mortgage in the US means that rental costs can be much more unpredictable than buying. Some people will -- very reasonably -- pay a bit more for peace of mind. And that's before we get into the topic of no-fault evictions, and how that can wreck a family's housing situation, sometimes with not too much notice.
Renter protections in the US are not great compared to in many other places, and that can make renting unpredictable and more "costly" in other ways.
A big problem with renting is the capriciousness of the rental market in many places, which you can't solve with "basic math". That plus the availability of the 30-year fixed-rate mortgage in the US means that rental costs can be much more unpredictable than buying. Some people will -- very reasonably -- pay a bit more for peace of mind. And that's before we get into the topic of no-fault evictions, and how that can wreck a family's housing situation, sometimes with not too much notice.
Renter protections in the US are not great compared to in many other places, and that can make renting unpredictable and more "costly" in other ways.