Also the default keybindings used by Emacs to do basic text operations are available in many places thanks to GNU Readline and Cocoa, which makes the experience more pleasant.

That's true. Although TBH, I'm not a fan of Emacs' key bindings. Some short ones like `C-a`, `C-e` are fine, but more advanced ones are difficult to memorize and force your fingers in unnatural positions. I prefer modal UIs and find Vim's keybindings much easier to remember and type. So for me evil-mode has been essential, and aside from some quirks, it works as well as in Vim. Readline also supports vi mode, which I enable in any app that uses it.

GTK too; but you need to enable it in GSettings (or maybe Gnome Tweaks under GNome).