[agentultra]

I'd wager than any such app that could help users migrate to a competing social network would be shutdown extremely fast.

Most users migrating their emails to another provider can do it through a desktop email client. At most it might require learning how to download an mbox file or some such. Pretty hard stuff for an average user, but not impossible.

Try telling a user that they'd have to program their own app on a proprietary third-party API and host it on their own servers and go through some sort of vetting process just to get a backup of their emails and... well I hope you can see where I am going.