Why are there less leaders generally? That is not intuitive to me since it feels like men generally want to fill that role in any context. Are there just less male dancers?
To address all of the peer comments at the same time: I don't know.
There are places where men dancing is gay-ish and that deters them. That's an easy answer, but it's not enough because very progressive countries don't do much better on this, by my experience.
I would agree learning to follow in the very beginning can be easier, so that sounds like maybe men don't remain because their job is harder, but I wouldn't agree with this explanation because I observe fewer men showing up for beginner classes, when they don't know their job might is harder (whether or not it actually is).
Maybe men are more asocial on average? I'd be willing to believe that, especially in these times.
A comment above yours comments that this isn't true in Turkey, Buenos Aires, and I would add Paris to this list from experience, and then there's the entire continent of Africa we haven't mentioned and I can't really comment on, but what those places have in common is a cultural presence of dance, often a deep connection to dance where families dance together, maybe mom dances when she's cooking, dance isn't something you pick up as an exotic hobby, it's just that thing everyone does, and maybe you decide to do it a bit more than others.
Every culture with a lot of cultural dance presence would have a different view on this, I suspect.
When the balance gets skewed too hard one way or another, lead/follow becomes less sex-discriminated. Which usually means that women lead too. But in the past few years it's become much more acceptable for men to follow as well, at least in some contexts.
My 2 cents on this question – it's easier to learn the follower part: you get some basics and then go to social dances events and practice with a good leaders. But to learn the leader part you can't just go to dance events and practice with good followers. It takes more deliberate practice in classes to get the leading part.
There are just fewer male dancers. I've gone to events with insane ratios either way (3x more leaders/followers) but it's rare. Usually there are more leaders at the beginner level and decreasing amounts as you go up (but more followers who can also lead to mitigate).
Every group thing where men play a big part alongside women or kids have a shortage of men. Men are simply way less social than women in today’s world.