Very interesting thought–I'd love to see how this dynamic actually plays out. I personally would welcome more contributors v.s. doing their work myself.
I think if a project maintainer were to act maliciously in terms of earnings share, developers would call them out and less people would contribute as a result.
I think if a project maintainer were to act maliciously in terms of earnings share, developers would call them out and less people would contribute as a result.