Please provide sources for your claims, that „most voters don‘t want housing to be affordable“ and „urban development is in the hands of councils mostly“. You can use websearch.

For me, my impression is different, considering Deutsche Wohnen & Co. enteignen and the state‘s reaction not to consider the public‘s interest, but to instead change expropriation laws to block the possibility to let it happen by demand of the common folk.
Maybe it‘s a systemic problem, have you considered that?