> Many open source projects are done without any good for the public

Such as? By definition, open source projects are provided to the public, for free. That’s obviously a good for the public.

Note that in order for something to be a public service, it need not be useful for every member of the public. Most people have no interest in curling, but that doesn’t mean running a non-profit curling club that is open to everyone isn’t a public good.