Because you are basing your assumptions that anyone could have bought on your own personal anecdotal evidence.
If I do the same i would say that nobody could buy their own house. My dad did various low paid jobs - factory work, bus driver, etc. My mum worked part time then full time doing various low paid work. We lived when younger in privately rented accommodation - 1 room when babies, then moved to 2 rooms without outside toilet shared with other families, no bathroom and no hot running water.
Then in slum clearances they were lucky enough to get offered a council house. They then struggled for years to pay bills, feed us all, heat home, etc. There were no working tax credits or anything except cb. They lived in a large council estate where everyone was prettymuch in the same boat. Nobody had money spare to buy a home.
Ergo nobody coulda fford to buy. Just because house prices were historically low does not mean that people had the income to actually buy. Even if buying would have cost the same as renting, getting a mortgage was difficult unless you had a good income or a wealthy guarantor.