Both VSCode and Atom are based on Electron, which is slow and battery-intensive as it is based on NodeJS. Are you saying that recent VSCode versions are as performant as, say, a C++ based editor or even (shudder) a Java based editor such as Jetbrains (Webstorm, etc.)?

I last looked as VSCode (on a KDE 4 CentOS 7 desktop) about half a year ago, and it was terribly slow, even without extensions.

I would say VS Code is far more performant than the Jetbrains editors in my experience on a 2013 MBP. It may be that the Jetbrains editors are "doing more", but I always found them frustratingly sluggish - maybe a worthwhile trade off when using something like Scala but I personally couldn't deal with it for Javascript.

I'd really recommend trying it again. On a performant machine, VS Code feels like a native app to me aside from a slightly slower start up time, whereas Atom is noticeably slow. On my bottom spec 12" Macbook the difference is more noticeable, but everything feels slow on there.

VSCode runs circles around Atom and Jetbrains both.