@nuukaset @scathach Rents getting absurdly high shouldn't be a thing without state backing, and it certainly can't happen if the scenario I proposed of limited rent property ownership is implemented. There's an objective cost for a house (materials+work) and only so many people who can own properties to rent before being unable to rent to anyone due to lack of demand, so if rent is as expensive or more expensive than the cost of building, then it makes no sense to rent at all.
There are countries that will always have a problem with it because their culture is like that (as you mentioned, the UK, where the same kind of impoverishing predation has been happening since the early medieval period) but in most places, if there's some degree of protection against outright usury, it's hard to end up in a situation where rent is so expensive in relation to the income most people have as to be unaffordable, unless there's a cartel of real state companies pouring the kind of money no individual can command into buying all available properties. If it gets there, it has to go down due to the simple fact that it becomes idle property and a money sink for the owner. The owner can then lower the rent or sell the property, and banks or lenders will take that chance to finance prospective buyers for the interest.