You're not comparing apples with apples. Its also the cost of the loan. I certainly remember interest rates at 15% - nothing like the lower rates today. Millennials have never seen rates anywhere near this high. Your argument isn't valid.
First time buyers with a low percentage of equity do not get the most favourable interest rates. Often ~5% even now. A higher effective rate than that of they have to use "Help to Buy" or whatever. And given that they're borrow such a larger multiple of their salary, this still means that they are paying a much higher percentage of their post-tax income on housing costs than any previous generation in recent history. Rents are driven by house prices and interest rates so the same applies to rental costs.
It's indisputable. The facts show very clearly that housing costs are are far higher proportion of younger people's budgets than they have been in the Gen X or Baby Boomer generations. This is a fact that is well documented and no credible economist disputes. So please stop trotting out your 15% argument as it convinces nobody.
Yes, that must have been crap and had an awful impact on lots of people. We know this. But - it was temporary. And those who survived the storm did very well. Surely you can understand that 15% of a small amount for a short time is less of a burden than 5% of an enormous amount indefinitely, if you can even get to that point??
I am one of the lucky ones btw, I have a very nice house. But please try to be rational about this: it is totally understandable why people are so upset about the multiple wrongs shoved onto their generation and, to add insult to injury, their parents generation on the whole blaming them for it rather than being ashamed that they reaped all the benefits while these problems were created and did nothing about it. It's embarrassing to read tbh. I remember learning all about climate change at school 35 years ago, doing projects about it for Blue Peter. Did the adults listen? Nope.