Even in the cities where the renter population is bigger than the homeowners, such as in Seattle, half of the votes come from people of > 65 years old (all of whom are homeowners, likely more than one home). Young people simply won't vote at all.
There is very little incentives for the young people to vote. Even if you cancel all the regulations right now and allow for unlimited constructions in the cities like Seattle, SF of NY, one will need about 10 years or longer to build enough apartments for the price to go back to affordable (which is 2-3 years salary of an average worker in the area). So the after-next generation will profit from the effort of the current renter generation.
Nevertheless, I think young generation needs to engage in the politics with the uncompromised goal to crush the housing price, to prevent the economic collapse of the "rich" world and prevent entire Earth from sliding into the dictatorship. Such is life.