I have very mixed feelings about this. I work in a library with a lot of patrons that are there all day due to housing issues.
Not in the UK, by the way, but in Canada. My American friends are reporting similar problems in their cities and towns. So I am hesitant to say this is just a matter of particular policy choices by particular governments. Investment in housing is an issue, but I think there is a lot more going on with it, from costs of materials to building regulations, but the number one thing I can see is drugs. The situation with drugs is far and away different than it was even 10 years ago where I am. And in other places around my country, the housing problem has similarly emerged as the new drugs have become dominant in that region.
There is a large portion of the population in shelters, and in tents, who have serious drug problems, or are mentally ill. Tent encampments tend to reflect that in a lot of places, what they bring with them are drug paraphernalia, fights, panhandlers, trafficing, prostitution, and so on. I've known people in low income housing where the tenters in the empty lot behind them would pee against the chain link fence between the two properties, in full view of the people in the houses; lots of tents just abandoned and left to be trash on the ground along with all the other trash from the encampment, and probably one of the worst things I've ever seen was a tent that caught fire because people were cooking drugs inside. (They were also selling drugs from the tent, but the police had been so hounded by the media for dealing harshly with the tents they would no longer deal with any of those problems.)
Banning tents isn't a solution, at the same time, I don't actually think it is ok for people to have this kind of thing going on in their homes and neighbourhoods either. People in that low-income housing aren't some sort of elite profiting from the labour of the masses, they are people in an inner city who want to be able to let their kids in the tiny back yard. The house across from the tent that caught on fire was a woman's shelter.