Yep, this is exactly the situation in the Seattle area. Here it makes little sense to take on a mortgage when renting is so comparably cheap. But go anywhere else like say Atlanta where rents are roughly equal to a mortgage payment and the opposite is true.
Generally you are right. VHCOL (Seattle, SF Bay Area), HCOL (California,...) and MCOL areas are better for renting and LCOL areas are better for buying.
There are two factors really:
- Rent to Buy ratio (or as you put it, rent compared to the mortgage)