I'm not wanting to start a debate, just to find out the variety of things that exist (and though I'm a long-time-Guiding member who hates they way they've gone on self-ID, I'm not asking about that either in this instance).
DS loves dancing, and goes to tap dance with a lovely understanding teacher, but he is also anxious and has SEN and has started to refuse to go if the other boy in the class (there are about 8 girls) isn't there. The other boy is often at competitions etc. (DS is not at that level) so quite often doesn't go. DS used to go to street dance with a lot more boys but the teacher asked him to leave as she couldn't cope (just her and a class of 20+ and he now has 1:1 support in classes he needs it in but this was before that).
About an hour from us there is a boys' street dance club and a girls' dance group runs alongside. That is too far for us to travel but I'm thinking of asking school if they would consider a music or dance class (they run sports clubs through external providers but no music or dance clubs) and if they'd segregate it into boys and girls.
Someone posted on a FB group I'm on that their school has boys and girls singing groups and, as an encouragement to school, I thought I'd see how common this is.
I know there are boys' ballet classes in London but we are miles from there. Just collecting examples, really. Any type of club (sport obviously is segregated at some age, so other types) so also cooking, craft, sewing etc.