In the latest Platformer I think ‪@caseynewton@mastodon.social‬ nails the nature of Twitter’s Substack self-own:

Musk’s chaotic overreaction to the mere development of Notes served to elevate an unreleased feature, overnight, onto an even footing with one of the most important social feeds in the world. And it will surely mean that more people play close attention to the product when Substack does launch Notes to the public.