Vim. I can never leave modal editing now. Been using it since 2010 and I think in vim when editing. It lets me enter a flow state so much easier. My brain maps into writing and editing.
Which is really counterintuitive when you look at how complicated the programs are. But I felt that it became better/easier than regular text editing after only 3 weeks of fulltime use. The uninterrupted flow of keyboard use, and reduced mouse navigation, feels great.
You only need to learn a very small subset of features to be very effective with it. Some people just stick to that forever. But you can also slowly add to it.
Every now and then I see the magic of modern text-editors (VSCode et al), especially with code completion /intellisense and file trees. For me, I rarely feel like I need to be able to complete function parameters in my code to be more productive. Code-writing takes up such a small amount of the creative process that I'm perfectly fine looking up seldom-used functions in a web-browser. I wonder if anyone has ever attempted the jump from longtime-vim-user to these and can share their stories about why or why not.
He's switched over to VScode with vim key bindings and has been happy as a clam. He's heavily using Python with pylance plus copilot for the python side of what we do (which is most things).
I'm an emacs user who has made a similar switch (but with a horribly weird mix of native and emacs keybindings). Oh, and the VScode sync extension for me. I use and love the rust-analyzer extension.
Switched to IntelliJ in 2018 when writing Scala. IdeaVim is fine, it even lets me switch to normal mode with jk/kj [0]. What more could I want?
I've been using IntelliJ for Scala, Elm, and Python, and still use (neo)vim for editing other languages and random files. I'm prepared to jump ship to vim+LSP on short notice.
[0]: https://github.com/tasuki/dotrc/blob/master/.ideavimrc#L5
My journey has been: VS Code, to Codium, to Atom, to Sublime, to now Vim where I feel the most productive.