Open Source is tricky, and can be seen through a few lenses:
1. Most open source projects begin as someone trying to “scratch their own itch” and solve some real problem they have. The open source part is just because if anyone else has the same issue, you might as well let them share your code and hopefully contribute bug fixes etc. It’s also nice as a way to extract bits of your day job that you think might be interesting in future work, and if possible, have permission to take that code with you to future projects even if that’s at a different job.
2. Open source is a way of doing work in the open, so it’s like your portfolio. It doesn’t matter if the projects are popular, their mere existence helps beef up your resume and gives you something to show off. This is especially helpful for folks without traditional credentials or loads of experience, and can help them skip ahead career wise.
3. Rarely, someone has an idea for a really valuable general purpose solution and wants to turn it into a business, and sees open source as a way to get the technology into the world, with monetization to come later. Perhaps there is a plan for monetization from day one, perhaps not. Not uncommon for B2C apps either (as a recent example, Clubhouse): worry about getting lots of users fast, and assume that, if you can, you’ll be able to work out monetization later.
The tricky part with Open Source is just for the tiny fraction that becomes super popular and hence becomes a critical dependency for the world.
For the handful that were designed to be businesses and had a monetization strategy in place from the beginning (for example, Sidekiq), this can work very well. But for most others, it’s a big problem.
The fact is that once you’ve given away something for free it’s difficult to monetize it directly. Maintenance is the killer. You have to either form a commercial steward to handle things - but then the monetization is tricky again - or you have to fork a broad community of volunteers who do the work for their own reasons. The fame is useful, but it can be fickle and difficult to harness.
Ultimately I think this comes back to the “starving artist” problem that is common in many creative fields. In general, it’s not that easy to find a way to make good money, so all manner of things fail because they can’t quite work out the economics or manage the business successfully. Think, for example, how many restaurants come and go every year.
This effect is greatly magnified for work in creative fields that can be distributed digitally. In the era of the Internet, the barrier to entry is so low, in the initial work of creating something new so satisfying, that you have an incredible explosion of work that people do for free. how many people start a YouTube channel and then fade away after a few videos! When one little part of this hyper-abundance blows up, the magnitude of supply versus demand just makes the economics and operational problems that much more difficult to work out.
Coming back to open source, this is why you see so much open source come and go. The person who was doing it for fun decides it’s not fun anymore, and since they can’t figure out a viable way to get rich from it, there’s no reason to keep up the drudgery and they move on.
So your question was, do you engineers have leverage? In the job market: absolutely, incredible leverage, and you see this manifest as wages that are vastly higher than the majority of people around the world can make. In open source: not really, because open source competes in a field of hyper abundance, which by definition means nobody has much leverage, and creating leverage is very hard (in the same way that successfully becoming a YouTube influencer is very hard).