If forcing social media to break their walked gardens doesn't work, maybe these two ideas could

I recently read “The internet con: How to seize the means of computation”. Doctorow talks about the problem of walled gardens (basically that you can’t write people on WhatsApp from Signal for example). He also writes that forcing this may compromise privacy protocols of different apps.

I thought of some more ways to improve competition:

• Force social media “providers” to allow users to make “out of app” automatic messages. It would make people able to automatically send “hey I stopped using this app, you can contact me with @ on [other app] [link that opens a message in that app to that user]. I think this could be the most powerful way. 1. It makes it easy for people to write you on the new app 2. It removes the worry that you miss out on people wanting to get in touch 3. If people see this more than once it becomes a social cue that people are switching which can have powerful domino effects (solves the issue of the illusion that everyone still uses it)
• Force syncing of stickers. Not everyone uses stickers. But it’s a powerful retention for the many that do. The fact that people have built up a library of their own creations of stickers and WhatsApp makes it difficult to transfer is a big switching cost for these people. If companies had to allow syncing of these stickers, it would reduce switching costs.