The extension by design is made to be optional to use and are not integral (I would argue) to the vanilla experience of VS Code. That also means that if other people wants to create their own proprietary extensions they can do so. The basic experience of the plain VS Code does not change. Now one can say indeed that the Remote and also LiveShare is the best extension there of, and since the extension author decides n…
Update:
On the other hand with Neovim being able to run headless you may just need that and VS Code stripped and use Neovim for the underlying editing and plugins if you really wanted to have a more open VS Code ecosystem. Kind of a hack, but it would work.