The fact it hasn't imploded a long time ago is proof that digital platforms need to be regulated to enforce interoperability.
Since this shitshow started, I have not heard from anyone that wanted to be on Twitter. In anything resembling a free market, these customers (both advertisers and users) could freely go to a competitor.
But due to the way platforms work, no one can compete, once a dominant platform emerges. A platform has a monopoly on all the things people built on top of the platform (content, software etc.). This monopoly kills the free market. Enforced interoperability would reduce this platform effect and help out competitors.
The EU is starting to tackle that, with the Digital Markets Act, but very few companies are targeted so far, even though the whole industry is plagued by quasi-monopolistic platforms that are universally agreed upon to be trash.