A shocking time has come - I've given up Emacs, after using it for 20 years. When interviewing developers, one of the questions I ask is about their favourite editor. I don't care what the answer is, but I do very much care about why it is. An editor is a fundamental part of developer productivity, so I want to hear about the candidate caring about their own productivity and trying to improve it on an ongoing basis.
The irony is that I was using the same editor for decades. I did keep trying to find improvements, but never could. There are two sides to Emacs - one is as a competent & coherent editor, and the other is "living" in it. It has builtin web browsing, image viewing, email and news support, terminal emulators etc. I was never one of those.
Before Emacs I used vi. Its modal interface, small size, and availability on all systems make it a good tool. However it was text console only, and didn't do colour, menus, multiple files or other useful functionality. (It does now.) vi does have a learning curve - I estimate it takes about 4 years to be good with it, and 8 years to be an expert!
I had known about Emacs for a while, but it was text console only, and didn't do colour, or menus. Each attempt to use it left me frustrated with what amounts to another arbitrary set of keystrokes. (I've always been a cross platform person so I was also juggling keystrokes for other operating systems and applications.) A colleague (hi Jules) introduced several of us to XEmacs around 1995. It had a gui, and colour, and most importantly a menu system. It was no longer necessary to memorize a large set of new keystrokes, as the menus showed them. You could do everything without knowing any, and then pick up those you use often enough.
By the mid 2000s XEmacs was languishing, and Emacs was slowly catching up with the gui. More and more packages only worked with regular Emacs (there were small but growing incompatibilities). I eventually made the switch from XEmacs to regular Emacs.
At the same time a new editor Sublime Text was introduced. It had fantastic new interaction (goto anything, projects, command palettes, multiple selections, distraction free) and a rich package system (written in Python - yay!) I kept trying it, but kept finding issues that affected me. Development also seemed to drastically slow, and since it was closed source there was no way for others to improve and update the core.
Ultimately tools these days are defined by their vibrant community, useful defaults, and easy to use extension mechanisms. Emacs has all those, especially in the past. But they are of a different era and different cadence.
I have switched to Atom. It had a rough initial exposure with performance problems, and the extremely dubious choice of being closed source. However both have been addressed. Just days before Atom 1.2 was released, I removed Emacs in favour of Atom 1.1. My configuration file is 10 lines long, and I get the same experience on every machine.