The issue I have run into a lot is that they have the “wrong” kind of experience. Somewhat inline with the adage “practice doesn’t make perfect, perfect practice makes perfect”. I spent a lot of my teens and 20s being introspective, working on myself, and becoming the kind of person I would want to date. A lot of people I have had experiences with in my 30s spent a lot of that time in bad relationships creating reactive responses to various things rather than addressing the core issues or learning how to, and as a result they often have a lot of “bad habits” or expectations going into dating or future relationships.
I have met more than one person that has said they need someone who can be patient with them while they heal and deal with their past, while also not necessarily wanting to, or being capable of, providing that same level of patience and understanding to a partner. That seems…uhhh not really appropriate or fair? But I’m the one that’s been single for quite a while, sooooo it’s just as likely I could be the one with my head so far up my ass I can taste my tonsils.