I suppose it depends, even those on 80-100k would still be living somewhat frivolously. Perhaps they use the money for kids colleges, paying off mortgages sooner, paying off car loans, paying of student debts entirely, perhaps even going on a holiday. Reducing financial stress would be the main target.

Also there's being able to retire >10 before others, or also being able to retire when others do but with more in the tank.

Above that any additional money allows people to again, pay things off sooner or increase their lifestyle. More holidays, latest gadgets, multiple cars, holidays etc.