which-key being integrated everywhere has made discovery the easiest of ANY editor/IDE I've used. Imagine if there was a consistent place where the menu would pop up if you faltered any key combination. If I'm trying to go a git command in Android Studio (InteliJ) and I forget the command, I don't get part way through and see a popup list of contextual actions. I'm left to move my mouse to the right place, click, and then hope to find my git action in the menu I picked.
More common is the unified way that helm makes dealing with files (you can find similar things in Sublime / Atom / Vim distributions using Unite (or whatever they used these days)). Even though the better editors have this, it's not universal and still a differentiating factor for usability and consistency.
Spacemacs integrates Magit by default. Magit is the first version control interface complete enough that doesn't make me immediately nope out into a terminal for proper git commands.
In my primary projects, I need to edit XML, Clojure, YAML, SQL, Java, Makefiles, and Python files. Spacemacs handles syntax highlighting, autocomplete, refactoring, repl connection and evaluation (where available), project management (makefiles and maven support), and documentation lookups.
All of those text editors above have some excellent and unique redeeming qualities. But at the end of the day their actual language support tends to be weak.
Now I do Python work in Pycharm, R work in Rstudio, and SQL work in whatever IDE goes with my database engine. I use Nvim as my system $EDITOR but at work I'm using it less and less often. I love it and I'll never give it up, but it's becoming more of a hobby tool than something that helps me get things done.
It's still fairly new so most solutions I've seen that use it still have some sharp edges.
I've gone pretty deep into both vim and emacs over the years, and so it always hurts a little when something like PyCharm comes along, and it works better, and does more out of the box than any finely tuned emacs/vim setup (which often take significant time investments).
I use vim for everything, but Intellij (because we have the licenses; I mainly use it for Python at the moment) has my attention. Wish I had more time to learn it; it has been a couple of months and I still don't feel really comfortable. But the capabilities actually make a difference.
Vim is never going away for me; muscle memory, if nothing else, ensures it will always be the most efficient way for me to type text and I spend most of my time in the terminal anyway. And as nice as it was when it was my go-to for everything, there are times when a special purpose editor has a place.
The trick is the setup, but I've only had problems with minor edge cases (like coffeescript 2). Either way I'll spend an hour and use Elisp to fix it. Really nothing I've found is even close to as robust
Spacemacs by extension integrates evil mode entirely, so keyboard macros are available.
The moment you start editing files containing more than one language you're pushed to use a dedicated IDE. And then you discover the joy of "good enough". No need to tinker with config files to get the perfect setup: it works good enough to give you a productivity boost out of the box.