Cheap cop-out. "some webmail provider" is what runs 99.999% of email. The people who run their own email, or run off hobby email servers, are insignificant.
You can't turn a blind eye to where the majority of users are going to be if you're implementing anything that actually needs traction in order to be successful.
No, there will always be a provider to webmail because there's demand for it. "Some webmail provider" is irrelevant, nobody is tlaking about people who run their own server here.
Federated social networks are like email: each instance is like the "webmail provider" you can pick and chose and some of them even come with their own clients and bells and whisltes.
Each instance needs a business plan (or a way for the user to benefit directly). Those that don't have one either disappear or never grow past a few dozen users which is not enough on its own to push the protocol's adoption.
Cheap cop-out. "some webmail provider" is what runs 99.999% of email. The people who run their own email, or run off hobby email servers, are insignificant.
You can't turn a blind eye to where the majority of users are going to be if you're implementing anything that actually needs traction in order to be successful.