If everyone had a requirement for marriage that you marry someone as smart as you, exactly no one would be married.
It reads as they're great and there's not a lot of people as great as they are when in reality it's probably more like the overlap between the set of people they desire and the set of people that desires them is impossibly narrow. This sounds like a tough personal problem that they can 100% work through by looking in the mirror and working on themselves.
I'm too great to ever find someone as great as me is frankly a piss poor attitude and outlook on life and I feel really bad for them to be stuck like that.
You could also simply have bad luck compounding the issue. Stuff any amount of effort or masquerade won't fix, like being a short man (inb4 "I know this small guy that...").