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.
Yeah, while I’m not a big hiker myself, being Swiss I know how prepared you need to be.
Walked around in Taiwan when I came across a hiking trail. 1.5 hours, like 150m verticality only, labelled as easy. Cool, but not enough water (only carried a 2l bottle). Went to a local teahouse and got me 4 more bottles to be safe and went for it. Walked past countless others because I was underprepared, and am glad I did because those could have turned out not so nice if I did go.