I think £65k provides a more than satisfactory life, if not a luxurious one. Two people combined on £65k are likely to have more disposable income than one of a pair on £65k and the other not working. A singleton on £65k in London would be more than OK but obviously would struggle to buy (at present) without help.
Depending on their life stage a couple on £130k would be able to live very comfortably, possibly not in London/SE with a £500k.mortgage and nursery fees.
There are so many variables and so many different perceptions and realities about living costs in various parts of the country. DS and DIL are on about £75k combined. Their rent is £2k plus bills for a one bedroom flat within 15 mins of Central London (their choice). Once their bills are paid, food accounted for, living costs dealt with, a modest holiday, etc, there is not much left. They are late 20s, no children. They would be stretched to start a family but they could move 10 miles out and get a much bigger flat, or could both switch careers and earn another £15k each but they are doing what they love. It sounds a lot but it doesn't go far in London, I am pleased they are living to salary.
There's a world.of difference between earning £100k in Newcastle and £100k in London. I remember when £100k was rare in the laye 80s. That probably extrapolates to well over £500k now.
Take the money out and define what represents a modest, comfortable and luxury life would be a more helpful exercise especially if adjusted for different regions. It's done for retirees but even then doesn't account for the size of property, etc.