I came across the interview with Henrik Lissner, the creator of Doom Emacs, and it really resonated with me about the biggest positive for Emacs (starting at 48:37):
The biggest positive for Emacs, hands down (that addresses all its negatives) is self-documenting, which primarily means documentation is a first-class citizen in ELisp. You can easily look it up any variable, function, macro, face, whatever, even something that's not defined in ELisp but defined in the C code you can look it up. [...]
If you use Emacs you're living in a REPL: you have direct, unfeathered access to its guts. And if you want to know anything about the current state of Emacs, you can just ask it directly. That's something I don't think any other editors can do quite at that level.
Living inside the REPL (or working inside a running program) is such a powerful technique in programming. That's also one of the reasons drove me towards Emacs after learning Clojure, even though the two LISPs have very different ideals or philosophies.