Banks make money by collecting a higher rate of interest on the money they loan out than the rate of interest they pay to depositors like you. They are not going to pay you 4% interest until mortgage rates go back up to 9% or more, like they were 30-40 years ago. You think you can't afford a house now? In 1981, banks had these things called 'all-savers certificates', which were like CDs, but had longer maturity dates on them. Banks were doing anything they could to get people to deposit money, and we had one that paid 14% that was good for 3 years. At that time, you couldn't get a mortgage for less than 16%, and even then, you HAD to put 20% down. FHA mortgage money actually dried up for a short time. banks really cut their margins thin between lending and paying depositors, they were so desperate for infusions of cash.
Nobody says you have to live in San Diego. You can move to many places where you can get a house that would cost $700k there for $100k - $200k, depending on where.