The median wage for an adult 24-35 who has a college degree is $84k-91k [1] and around 40% of 30 year old have college degrees. If your making 90k you can even save 7k a year in HCOL places like NYC and Boston if you live well below your means. I.e. lots of people would just use that disposable income on traveling/ eating out/ concerts etc but if your a homebody and live with an SO or don't mind commuting and cooking most of your food 90k goes quite far with no kids.
https://www.bls.gov/opub/ted/2025/median-weekly-earnings-by-...