I think there should be more affordable housing. Something in between a council estate and a normal apartment building.
Here ion Frankfurt I live in affordable housing, built by private companies but with special benefits from the state or city council.
You need a certificate to live here and can't earn more than a certain amount. The rent is reasonable, the location excellent and the view is amazing, I get the whole Frankfurt skyline plus the city forest.
Getting the apartment was also super simple, filled in a form and the week after signed the contract and was given the keys.
I pay 580 euro per month (including water, heating and maintenance services) and 42 sq m just for me.