Because tech debt is real... V8 exists and likely isn't going to be completely displaced as a whole. That said, I can't speak for what are or aren't priorities for Google... I'd say they and Apple both have every incentive to give a good experience, and how far that is from the "best" experience will vary.

> Bun.js uses the JavaScriptCore engine, which tends to start and perform a little faster than more traditional choices like V8.

Little faster? Like I said, that's not a *main* benefit as it's not why Bun can be 5 to 10x faster than Node.js