(c) Emacs won't disappear after a few years (where "few" can mean decades if your career lasts that long - mine ran from 1967 to 2011 and I still use emacs daily) the way virtually every (or maybe every) "more intuitive" editor/environment will, given time. Your investment in learning it will really pay off.
Adoption rates of intuitive IDEA and Visual Studio, while not quite as old, have long pushed Emacs into niche territory. Emacs hasn't disappeared only in the sense any venerable UNIX utility hasn't.
Not to say that you should use Emacs instead of VS Code or anything else. Just that Emacs not disappearing means that your investment to learn it and set it up is more likely to keep yielding returns.
If existence is tantamount to corporate sponsorship, then GNU Emacs never existed. It'd take one or two graybeards with too much free time to sustain Atom. Just look at the current Emacs maintainers.
What do you mean by this? The emacs-devel list looks like a smart and generally well run project.
Perhaps. Does Atom have said graybeards? The motivated ones are hard to come by.
"hasn't disappeared only in the sense any venerable UNIX utility hasn't"? "Only" doing a lot of work here! That's the most reassuring "only" I've read all day. I bet you a pound people will still be using Emacs in 2050.
Though all of that, I have used GNU Emacs, definitely an unconventional choice for Java development. I've occasionally tried the leading IDE, and while it's sometimes been helpful to ramp up on new projects with tools shared with other teammates, the productivity of a comfortable and customized Emacs environment has always drawn me back.
In 10 years, IDEA and VS may or may not be still widespread, but Emacs will definitely still have its niche.