How do housing benefits work in the UK?

[Espressoroast]

Trying again - genuinely not trying to be goady. I’m not from the UK and my home country has a very different system.

I am a nurse (band 5, NHS) and have a colleague who lives with her mum, both also Band 5, full time employment. They’ve been in a council flat for ages (10+ years) and been both employed that whole time. I would imagine there are others who need the housing more urgently or are less able to pay on the privat market?

In my country, housing benefit must be reassessed periodically so that if you make more than a certain amount you will pay market rate and be asked to leave funded housing. Is that not how it works here? What are the benefits of the system this way?

If SH was just for those who are in reciept of housing benefit (even a contributionary amount) can you imagine the loss of money for local autorities? Rent paid in full is beneficial as it is put back into social housing i.e building more, home adaptaions.
Where I took the pic ture from www.middevon.gov.uk/media/351593/annual-accounts-2019-20.pdf

I live on the same kind of estate as @dangermouseisace. The idea of people around here sitting pretty paying low rents on £60k-plus incomes is laughable, though I daresay there are isolated cases elsewhere in the country. The rational if not ethical decision for someone in that position would be to buy the house, not to move out and pay rent to a private landlord who might want them out at his/her own whim. That doesn't help the supply of social housing, does it?

There are certainly pensioners occupying bigger houses than they require, but that's because they've been on waiting lists for smaller places for years.

I would also be very very surprised if anyone on my council estate is earning 60k plus.