[dane-pgp]

I'm not sure how strong those arguments are, actually.

* Interoperability is feature just like any other, and the difficulty of implementing/maintaining it must be a fraction of the difficulty of competing with the network effects of entrenched online services. Indeed, I would hope that interoperability would pay for itself, in terms of effort, because of the number of users that can migrate to the new service, as well as being a selling point in itself (since people would be reluctant to sign up to yet another incompatible silo).

* I think incumbents don't need to rely on interoperability to do market research and copy features of competitors. It's true that Facebook would be able to see private posts on Mastodon instances that it federated with, but I don't know what useful data Facebook could gain from that which it couldn't gain from A/B testing its own huge user base. If anything, I would expect Mastodon instances to gain more from this exchange, because they are gaining access to the bigger pool of data.