luceos We have seen people get careers in development after starting out with Flarum extension development. So yeah, with motivation and persistence, you might actually make a living off of it regardless of what it is you undertake.
I started out many years ago with a different platform. Initially, I was just employed as a support person, writing documentation, helping with customer support, etc.
Eventually, one of the server devs was having issues with some new tech, and I knew the answer. I messaged him in private, got to talking, and fast forward about 10 years. My job is to look after more servers than I think is safe....
I started out as just a user of an add-on that opted to try to help a few people with similar issues and learn (again, a different platform, not Flarum) as I went.