I was thinking about that when I was dropping my 6 year old off at some hobbies earlier - it’s pretty much expected to have learned how to ride a bicycle before starting school, and it massively expands the area you can go to by yourself. When she went to school by bicycle she can easily make a detour via a shop to spend some pocket money before coming home, while by foot that’d be rather time consuming.
Quite a lot of friends from outside of Europe either can’t ride a bicycle, or were learning it as adult after moving here, though.
edit: the high number of replies mentioning “swimming” made me realize that I had that filed as a basic skill pretty much everybody has - probably due to swimming lessons being a mandatory part of school education here.
Swimming. My brother in law is from India and he never learned how to swim due to him growing up in a place with only one extremely dirty river and no other lakes or swimming pools near his family. Apparently no one in his family can swim. He kinda can swim now but it still looks funny. A bit like I must have looked from the outside when I learned to swim - as a six years old. I always found this very odd because the dude is smart, hard working and has a degree but it took years and him becoming a dad to realize that swimming is something pretty much everyone can.
Better that than being unable to (such is my dilemma).