Similarly, I'm also bothered by the common argument that participation in sports is vital for learning to work as part of a team, as if STEM projects don't facilitate gaining such experience.
The argument is wrong in a different way too: there are non-team-sports in which you can participate by yourself just fine, while reaping all the fitness and health benefits.
Eh, in a high school setting, there's no better way to learn teamwork than being on a sports team, imo.
Mainly learning about winning and losing and trying again.
There are other "teams" you could be on: drama departments, school bands, etc.