You're right in the sense that it isn't just a transfer of wealth to the elderly, it's a transfer of wealth to home owners, particularly in the prosperous parts of the country, and in the long run to their families. In the short term that's correlated although not matched to young/old, and it gets more and more fuzzy the further into the future you go.
Ironically in effect the left wing party just made a lot of political headway by allying with the right-wing tabloids to protect this inherited wealth against being used for care of the elderly. There are better ways of organizing it, but I didn't hear much nuance in the campaign against it, and I wouldn't be surprised if all policies even vaguely similar are now dead in the water.
It's also in reference to the UK, where publicly owned housing was sold off to tenants in the 80s at below market rates, and housing markets have been booming ever since.
Ok, that's got to be the weirdest mental gymnastics I've seen for justifying rich old people running the world. I'm also suspicious that's it actually true because I'm sure a lot of houses changed hands in the US housing crisis, and it probably went to real estate brokers who decided to rent instead of sell even after getting a bunch of houses in the firesale.
Even if old people realized those gains by selling their house (and going where?), it's not going to be enough money that they'd go out and start buying a bunch of other houses and charging outrageous rent. Certainly not enough to lord over sprawling apartment complexes filled with a bunch of millennial wage slaves.
Maybe, maybe someone in California bought a house for like 50k and turned it into life-changing millions, but to imply that's a massive transfer of wealth for entire countries is disingenuous.