@Halloumiheaven
The hard truth is, it's self made
You really can't make a sweeping generalisation like that. Especially these days when basic costs of living are so high. If people can barely afford the essentials/necessities, they aren't in a position to buy a house to rent out, are they?
My son has just finished his first year in a professional job with on of the UK's biggest insurers. On a pretty good wage for a graduate job. He has literally nothing left after paying his rent, utilities, transport, food, etc. His "discretionary" fun spending is about £100 per month, so he has to choose whether to go to the pub quiz or whether to go to five a side football, he can't afford to do both.
None of that is down to a lavish lifestyle or overspending. His flat is a tiny one bedroomed with kitchen area in a corner of the living area. Right on the edge of town, the furthest away possible from the town centre on anything remotely like a decent bus route. It takes over a third of his wage on rent alone. Utilities come to something like £500 per month being £100 on electricity despite him barely having the heating on (it's a hugely expensive electric water heating system, no gas, and of course, it's rented so he has to put up with it), council tax something like £200 per month (utterly crazy for a tiny flat, but it's an expensive city), £150 or so for water rates (not metered, so he's paying for 2/3 people- again outside his control as he's renting), £50 for internet as he needs speed and reliability due to having to work from home 2 days per week and study from home, plus insurance, mobile phone sim card at a tenner per month, etc. He can't cut down his food bill - he already gets everything from Tesco using clubcard discounts, takes his own packed lunch to work, never buys coffees or other items during the working day, a cheap takeaway only once per week. It's a ridiculously frugal lifestyle for a graduate professional.
Heaven only knows how single people on minimum wage can afford to exist unless they're still living at home, which is impossible for lots of professional graduates as the decent jobs are centralised in a hand full of major cities, so they have to move away for decent jobs, or have to stay living at home and end up working in retail, hospitality or care at minimum wage. What an awful choice for people whose home towns are in the run down regions!