Leasehold houses are a crazy idea and the government should certainly have stepped in early as developers began selling the freehold (and thus the entitlement to receive ground rent
indefinitely) as an investment. Historically most of these leases were "peppercorn rent" which means they had some notional requirement of rent to be paid, but you were not in fact expected to pay rent. But legally
any consideration works, so if you can charge a peppercorn (as a legal fiction to make this a contractual arrangement between freeholder and leaseholder since cutting up the freehold was for whatever reason impossible) you can charge £250 per year. Or £1000 per year...
Because the government didn't step in early and say "Oh, that's just an obsolete feature, you can't do that with it, we'll remove it" and pass legislation in say 2005 to set the maximum ground rent at a notional £1, the "investors" got bolder. They added escalator clauses, after all £1000 per year is a nice earner today, but it won't be much in a hundred years, so let's say it doubles every 25 years to account for likely inflation plus some profit.
Actually wait, the idiots are still buying them, let's say it doubles every 10 years.
And next thing you know, some of the people who "own" a house are paying almost as much rent as people who don't "own" a house, oops.
Funny that the property owning, rich investor classes in the Tory party don't seem to be in a big hurry to actually fix this, although they do say it's a "Priority" (like everything else) when confronted. I wonder how much money Rishi earns every day from this "mistake" that he never got around to doing anything about as chancellor for example...