Obviously extensions.

And it's not "reimplementing" the whole IDE, it's choosing and configuring parts to work just the way you want it to, and it's usually done in a handful of lines.

a handful of lines + the additional processes that do the parsing behind the scene. Just because it's split across multiple processes doesn't not make it an IDE.

It's 8 lines of config, more than half of which are cosmetic customizations for colorblindness accessibility that I'd need with an IDE anyway.