Not wishing to invoke a pile-on here, but there are non financial rewards in Open Source.
- Love of the craft
- Intellectual curiousity
- Developing your own expertise
- Giving back by mentoring others
- Being part of a community
- Plain old altruism
None of which may have a immediate monetary reward. There is also the possibility of monetary reward in the future. Benefiting others being rewarded financially are not always mutually exclusive.
It's also not a binary thing. You absolutely can have a day job (coding or other) and do a bit of Open Source on the side. Or even work in Open Source full-time. Much of the developers I correspond with day-to-day fall into this category. Employed by big (or medium) tech, working on Open Source projects.
Fulfillment in life tends to come from a variety of sources. For me, the main one is my wife. There are many other things that give me fulfillment, and that includes Open Source. But you do you.
If I were a millionaire, I would still be doing Open Source. But I did it when I was poor as well. 🤷♂️
Open-source is for millionaires who have enough money and looking for ways to achieve fulfilment in their life.
Us, working class, don’t have the luxury to code for free.