My husband is a high earner, I earn an average amount. When our initial relationship became more serious, and we first made a monthly budget/shared finances info, I was really shocked at his spending vs his savings.
It was lifestyle creep for him in the finance bubble, plus living alone renting a nice 2-bed London flat, travelling, eating out all the time, and enjoyed his money/life/experiences after growing up quite poor. I don't really blame him, but it was a shock to me as I am the polar opposite & quite frugal.
I don't believe there's any reason someone on over £100K should be 'struggling'. Realistically they are 'struggling' to keep up with their social circle who may have private/prep school/beautiful holidays/new cars on finance/new kitchen/huge mortgage, but they shouldn't objectively be struggling and living paycheck to paycheck?. I do however accept nursery fees are a killer.
Now, with our combined income, I manage our finances, we are able to live on his wage alone, and save all of mine. Security is important to us, we could have bought a flashier house and maxxed our mortgage affordability, brand new cars (we have two old fords paid off), and renovated our house quicker, but we choose to have savings in the bank and don't care about keeping up with the jones'. I don't see how people in our position are living paycheck to paycheck, we've never had any family help financially either, we've just learned to cut our cloth appropriately.