Well, you could teach that sport to others (as a part-time coach for amateurs, for example), you could create training videos and materials, write books or a blog with tactics, tricks etc. If you're not the only person in the world into this sport, I am sure there are many other people who share your passion and would be happy to pay you for materials or training as they themselves will only have limited time to invest in it. You don't have to be a pro yourself. If you're not a total amateur, there will always be people who know less about it than you, are new to the sport etc. and they can be your audience. Also, consider looking at organizations adjacent to that sport or sports in general. There are a lot, from youth outreach NGOs to sport centers, to clubs where you could work as an assistant or clerk but still your work would have to do with the sport itself. Again, this is unlikely to make you rich but might be an option to work in an area you like. And who knows, even if you won't be a world-class athlete yourself, you might manage, teach or support one, that would be pretty great as well, no?

I understand and accept what you say about the high-paying all-in job option. It's not for everybody and can also be damaging.

If you want part-time dev jobs, of course they're out there's lots of competition and not necessarily a lot of job safety. The lowest end are gig economy jobs (like Upwork and Fiverr) but again, buyers there are sometimes also looking for an easy, reliable, part-time go-to guy for regular jobs that maybe have a unique skill set. You can always give it a try. Chances are that you will not make enough money doing this (most likely) to live comfortably in a highly developed country (I don't know how to express this in the "political correct" way du jour but you know what I mean). However, the advantages are guaranteed 100% remote and no long-term commitment, so if you find something better, you can always take it.

Wishing you all the best. And seriously, do report back some time how it works out for you. I'm sure many have the same dream and wonder "what if..."