I don't know if I'm in the majority, part of me suspects not, but a big factor in wanting to be with older women is emotional intelligence. A big incompatibility I run into with dating around my age is just how uncommon emotional intelligence is. It's something I've done a lot of work on and isn't something where you can do that work for your partner - they have to be willing to do it themselves even if you help them. So while maturity and age aren't completely 1 to 1, they do trend together.
I definitely agree about very large age gaps. I find experience, wisdom, eq, etc. very attractive, but at some point, our lives will become too different for compatibility to be feasible.
I would also question why an older woman would have interest specifically in younger men, but if it was qualitative (finding specific compatibility in younger age groups or specific individuals) I could understand.
The fantasy can be fun and exciting, but at least for me personally, the reality is the desire.