I don't think childhood standard of living is relevant. If pensioner 1 grew up in a slum and pensioner 2 came from a wealthy, privileged home, if they both end up in the same situation at 70 we wouldn't say pensioner 2 didn't deserve the same standard of living.
Compared to kids from low income homes in the 90's, those living under the current reforms and those who grew up in the 70's/80's had a much tougher time, but I don't think anyone would suggest the latter groups should have better retirements than the 90's generation.
Ll that's not really reflective. When dd was a baby/ toddler I kept 2 of us on similar to state pension. But as a young, active person I had avenues open to me that many pensioners don't. Even hauling heavy shopping, and the energy to go round dozens of cheap shops isn't an option if you're elderly and isolated. I bet my shopping for 2 cost less than a pensioner limited physically. Even if I was too skint for petrol I could walk, or dress up warm and go to the park for hours if I couldn't afford the heating all day in winter. If the washer or fridge had broken I'd have walked carrying stuff on the pram till I could replace it. Many pensioners don't have those options.
Also if you've ever lived in real poverty, the one thing that keeps you sane is knowing it isn't forever, but for pensioners it is so they need an income above survival.
Practically anyone can live on £20 for a week, or £70 a week for a few months. It's when it becomes a year or years that physically things need replacing, and that mentally it gets hard.