There is so much more to this than interoperability. Both Twitter and Meta have strengthened the spread of disinformation and the forces that endanger democracy on an industrial scale. Mastodon with its different model is a fundamental alternative to that - and for a lot of people that‘s why they invest time and effort here, not there. Once connected, Mastodon won‘t be a systemic alternative any more, like an organic food coop becoming a Walmart stall.