[dmitriid]

It won because most developers don't know any better.

The main reason is Language Server which allows you to quickly bolt on some simple autocomplete+refactoring functionality for almost any language. And this is already a magnitude better than what was available for most languages in most editors. Even if it's a tiny percent of what an IDE like Intellij IDEA is capable of.

I may hate IDEA's sluggishness, but the insane amount of tools at my disposal trumps anything VS Code offers even for the officially supported languages.