(Graphical) IDE's are great for development, but they're slow to start and heavy to run. Sometimes you just want to take a quick look at an xml or dockerfile and you don't want to spin up the whole IDE for that.
I've recently rediscovered notepad++ for that (on windows), what's your prefered easy-acces-tekst-editor?
Yeah, I'd call Emac and Vim both IDE's. They're definitely not "just" text editors.
Vim can have some IDE-like qualities, if you bolt enough plugins in to it, but by default it affords buttinx text in a file and manipulating it.
I woudn't classify it as an ide though.