Here's Cory Doctorow on the legally-backed technical interoperability barriers that social networks use to maintain and enforce their walled gardens: "we focus too much on network effects, and not enough on switching costs."
New proposals from the UK Competition and Markets Authority, as well as the EU's Digital Services and Digital Markets Act and the US ACCESS Act of 2020, all contemplate some form of interoperability mandate – forcing the dominant platforms to open up the APIs they already use to let various parts of their own business talk to one another. These mandates are a great floor under interoperability, but they can't be the ceiling. That's because they would be easy for big companies to subvert: if a lawmaker forces you to open a specific conduit to your competition, then you can respond by moving all the interesting data away from that conduit. You're still providing a jack that competitors can plug into, but you've moved all the important stuff to another jack.
A network effect is just a switching cost with a TED Talk.