How is being a landlord pure greed ? They are providing a service.
No. No they aren't. If they were, they would all
Accept people on benefits in at least a proportion of their properties
Keep their properties in good condition - no mould, do repairs promptly, not leave problems like woodworm to remain untreated until houses are unsafe, install decent appliances & get them serviced & not leave families without heating or hot water for several weeks in the winter
Allow pets
Meet their legal obligations, e.g. gas certificates etc.
DH, DD & I were homeless this spring, despite being able to pay market rent locally & having a perfectly good credit record, no missed payments at all, ever, in nearly 20 years of renting. Our LL sold the house, as worried about Brexit & future property prices. But we're on benefits (I'm disabled). We couldn't find anyone who'd consider us. Thankfully, eventually, we got social housing. After some while in a shelter.
Private LLs are not "providing a service ". They are making money, for themselves. Hence it being so attractive to investors.
DH & I have literally never had a good LL. Hoping that as we're now in a HA house, it'll be better. Obviously, I'm sure there must be some good, honest, responsible LLs. I've heard about them like an urban myth