Besides what's everyone has said so far, what I love the most about my emacs is that the only thing I have on my screen 95% of the time is code. No side file tree, though helm find files has a sweet UI I use hundreds of times a day. Magit is there in three key strokes and out when I'm done giting. My window navigation is sweet. Sometimes I have zero splits, sometimes I have a dozen, and it's easy to navigate between each split, resize them, undo split modifications etc. My flycheck shows me errors in a great UI when I need it and doesn't show when I don't. Same with helm-imenu that that shows me classes, functions, methods and attributes when I need them and only then.
I'm sure you can do that with all the editors, but when I see peeps using VScode or myself using Xcode, everytime close to 50% of the workspace is filled by stuff I only need temporarily.
Emacs let's me see code most of the time, yet has all the classical IDE features one could dream of. <3