I went (10 years ago) JetBrains because of emacs. Back then, they were the Kool Kid in town that made emacs-style functionality more accessible.
More and more they've become just another IDE with too-much-to-do. Still one of (the?) best, but as soon as your editor becomes impractical to use to edit a text file... (because it really just likes to work on projects...).
But yeah, emacs remains functional in a way that JetBrains...probably won't. I'm already more than several years behind on their releases because they stopped putting a decent product...
Oh boy, I was such a jetbrains kiddo, I can't even tell you. I had posters on my wall with keybinding and commands cheat sheets, I knew people working for JetBrains by their names, I talked to them regularly, it almost felt like we were on the same team. I tried to debug and understand plugins, even wanted to develop one, but somehow never got to do that - the hacking mindset of a habitual programmer just wasn't there yet - I kinda went with the status quo - "if IntelliJ doesn't have this feature, maybe I don't even need to know about it..." I've discovered and reported so many bugs on YouTrack, I still receive updates on them, even today - some of them date to 2009, things that JetBrains never even tried to improve since then.
WebStorm was probably the biggest reason why it took me so long to switch to Emacs. My biggest fear was that if I invested in learning Emacs, and at some point I'd inevitably find that something simply couldn't be done in it, and I'd be forced to go back and my idyllic life would be ruined. God, how wrong I was. Not only have I found _everything_ I needed, I actually discovered radically different ways of solving problems.
In the end, turns out one thing jetbrains did right - they have nailed the marketing - I surrendered without resistance. My biggest regret is not trying out Emacs sooner. I wish someone very persuasive showed me things I did not know were possible. That's why I get very vocal about it - kids have zero idea what they'd be missing.