First of all, I know people who've done like 0 gender exploration by like 50, so like LMAO
Secondly, if someone arrives to the conclusion they're trans, chances are they have explored their gender. One doesn't wake up and say "I'm trans". They think, they try it, and they may leave it like your friends did. Also, like I'm assuming you're cis... Just saw you're Iapetus, ok, Ik you're cis LMAO. Well, as someone who experiences both gender euphoria and "attraction" to women, they're different AF. Like genuinely, the feeling of burning desire of being horny is so different than the warm sensation of weightlessness whenever I'm called my name. Like also, something I don't have any studies to prove, but I have seen a whole lot of is that detransitioners tend to transition bc of dysphoria, not euphoria. And a dysphoria like feeling can come from like a trillion different things, from internalized homophobia to just feeling ugly. Euphoria is much more of a direct and visible correlation.