Atom was based on web tech, like VSCode, while Zed is a native app with a custom GUI framework, just like Sublime Text. And just like ST, the standard option now for a fast barebones text editor. That's what I mean by 'spiritual successor'.

Isn't extensible plugin API part of ST spirit? (so zed can't be a successor until its spirit incorporates a similar one)

Its funny how the same guy who wrote (borderline) the slowest editor, went ahead and built the fastest. Practice makes perfect I guess :)