To be clear, I wasn’t trying to say ALL rental housing should be subsidised, just that there should be a healthy supply available for local councils to make available to people who need it based on whatever criteria they set for that.
Even when I was renting, I’d earn too much to qualify. People with young children would take priory over single people. That sort of thing.
It’s not a perfect system, but it’s better than companies gaming the system to maximise profits at the expense of the most vulnerable.