1. The creator has a real, solid way to make money (React by Facebook, Go by Google).
2. The project is extremely popular (Linux, PostreSQL).
Is it possible for people to reliably keep working for ~free? In theory yes, but if you expect that, you have a very bad understanding of 98% of human behavior.
They are making lot of enterpise bucks though. And they did start as Open Source. Killing it midway to serve their convenience is the issue.
There's also tonne of Open Source that isn't as popular but serving niche communities. It's definitely harder but not impossible. OS core and paid hosting with bells and whistles has proven to be a good sustainable model.
There's actually three ways, the third one being academia picking up the bill which is how we got the mess that is OpenStack.
Also, Debian has been around for a few decades, although I do admit that - like the Linux kernel - that wouldn't have been possible without a lot of companies contributing back to the ecosystem.
There are two ways open source projects continue.
1. The creator has a real, solid way to make money (React by Facebook, Go by Google).
2. The project is extremely popular (Linux, PostreSQL).
Is it possible for people to reliably keep working for ~free? In theory yes, but if you expect that, you have a very bad understanding of 98% of human behavior.