[dredmorbius]

Emacs is a very general and fundamental tool. It's "do one thing well" is "organise textual interactions, via lisp". And that ranges from editing to shell to numerous programming environments to email to web....

I'm actually thinking of picking up Emacs again as a preferred option to a browser.

Eclipse and Intellij may be open source (and I'm sufficiently unfamiliar with them that I'd blown that fact, thanks for the correction), but they're far narrower in scope. That itself tends to be a strike against. Even broadly-used tools -- say, Perl -- can be, pardon the term, eclipsed by others.

Mind to: learning multiple ways isn't a Bad Thing. But being highly mindful of what tends to survive and what doesn't is itself useful.

Emacs dates from glass TTYs, and has survived to mobile devices. I've seen enough of other tools to note the quirks of their own tech origins and how this has or hasn't limited them over the years.

So: consider mine a somewhat informed, somewhat uninformed opinion. Though I'd still strongly recommend Emacs as a durable, extensible, and exceedingly useful skill.