The protocol example is a good one. However I don't think it's the network effect that's beneficial in that case but rather the innovation of the thing that was built.

If it's closed, I think that facet specifically is detrimental to the consumer.

If it's open, then that's the best you can do to mitigate the unfortunate reality that taking advantage of this particular innovation requires multiple participating endpoints. It's just how it is.

Moreover, they shouldn't have any way to force (or even nudge via defaults) the user to use Apple Payments, App Store, or other Apple platform pieces. Anyone should be on equal footing and there shouldn't be any taxation. Apple already has every single advantage, and what they're doing now is occupying an anticompetitive high ground via which they can control (along with duopoly partner Google) the entire field of mobile computing.