Sure, we do all stand on the shoulders of giants. But the other things I listed requires significantly more research and development effort than building an IDE does.

Also I dispute that VS Code is the quickest editor out there. It’s faster than its Electron counterparts but that’s a pretty low bar. This isn’t a dig at VS Code, it’s my default IDE (well that and vim). But the largest part of the reason I use VSCode is because it’s free.

That, for me, is its real advantage. But that’s not an engineering achievement.