To what extent is an age gap a red flag?

A lot is said about women being post their prime in their thirties but this is rarely mentioned for men. Now of course men and women arent the same and the same criticisms don't necessarily apply, but I think quite a few do.

We generally look for a mature man able to provide and ready yo settle down and those obviously come with age but there's a lot to be said for missing out on the kind of passionate puppy love that happens in ones youth, for never being the fun wild girlfriend he partied with till the morning and for the good men being snatched up early.

Im stuck between feeling like im missing out in dating an older man and worrying ill get dumped and upgraded in dating an age matched man.Any thought? What are some things to watch out for when asking an older man why hes still single at this age?