[trelane]

Emacs is a full IDE, not just a quick one-off editor. Its power comes from having everything scriptable from the ground up. Contrast this with the modern Extension concept, where there is a hard line between the editor's code and any changes you might want to make to its behavior.

I think vim is probably similar, but I've not gotten into it that much.

[bilekas]

Exactly, and infact vim is very simular, neovim in my case extensible through lua scripts as an example. It's as light or feature packed as I like.

Contrast that to Eclipse and Visual Studio (not vsCode) and it's clear why the larger IDE's are falling out of favour.