What are some of the more popular non-commercial cultural things you're aware of?
This could be things that once were commercialized but are now public domain, or have largely resisted commercialization to this day. In this context I mean this as aiming for profit and being sold/monetized.
Solid fun at any skill level and very modest cost. A round of disc golf is basically an excuse to go for a nice walk while hanging out with friends or even solo.
You can buy a few discs for 10s of dollars and can even share them if you want. Courses are everywhere (at least in Canada, but I suspect elsewhere too) and usually absolutely free. Discs are portable enough to take whenever you visit a new place. If you want to get serious, you can spend a little more, get more discs or a fancy bag, go to tournaments, but it is still cheap compared to almost any other sport and really hard to spend much money on.
I am absolutely terrible, but I get better every time and I have so much fun.