The point is, steam competitors don't do badly because they lack the man hours of steams Dev team. They do badly because of terrible company vision and incentives. Open sourcing a tech doesn't solve a problem that doesn't exist. I don't even think open sourcing steam really does.. Anything, for developers. Philosophically cool, practically useless, everything that steam is exists in piecewise form already. Turning steam into a federated service is not meaningfully faster because you make steam open source.

Gog is the closest and does fine. The technology is about on par with steam, the philosophy of the service better, and they are doing fine. Not overwhelming steam no, but fine.