Atom predated VS Code and was the impetus for Electron, which VS Code uses. You may know this, but this comment makes it seem like they tried and didn't have an opportunity. They literally invented what the majority of new "desktop" apps uses to render UIs, they just couldn't compete with Microsoft (before they were bought out, after which of course Microsoft wasn't going to invest seriously in it).
Edit: Fixed typo (thanks torstenvl!).