Those keybindings work on MacOS for me, but not on Linux (by default).
There is a way to enable Emacs keybindings in all GTK apps on Linux, but it’s quite buggy in practice (many apps define keybindings that override or conflict with these), and I believe the feature is officially deprecated.
Yes. Basic emacs keybindings work pretty much everywhere in macOS. I have run into a couple of apps that don’t behave correctly, but 99% of the time they work.
I have been using VSCode for teaching the last few years, and routinely use a VSCode without plugins for that purpose, and Emacs keybindings work fine in its text area (the code editor itself). If it doesn’t work for you, then apparently something is broken on your computer. Not all keybindings work but the ones listed under Text Editing here certainly works for everyone else:
https://support.apple.com/en-us/102650
I am typing this in a textarea in Chrome, and the basic Emacs navigation commands all work: C-a, C-b, C-e, C-f, C-n and C-p. (The M- equivalents don't, though. You just get some special chars: å, ∫, ´, ƒ, ñ (dead char for the accent), π.)
Chrome Version 149.0.7827.155 (Official Build) (arm64)
Very similar in Visual Studio Code.
(I started using macOS in 2010, I think, and the Emacs-style shortcuts have felt pretty well supported the whole time. I can't promise that applies to Chrome as well though, as I'm not a regular user.)
Yes. For me, on all MacOS versions from Catalina to Sequoia, the basic Emacs keybindings listed here work almost* throughout the operating system:
https://support.apple.com/en-us/102650
I don’t daily drive VSCode but I use it for teaching, and then basic Emacs keybindings like C-n and C-a and C-k work pretty much everywhere, from the command palette to the code editor, without any plugins.
I also don’t use Chrome as my daily driver, but keybindings like C-a/C-e certainly work in both text areas and address field, or I would have remembered it as one of the annoying exceptions. I do regularly use a few Electron apps, which are based on Chrome, and it does work fine there.
*: There are a few apps that deliberately break the Emacs keybindings. Microsoft Office is one of them, since they insist that Ctrl keybindings on Mac should do the same as it does on Windows, which is extremely jarring if you rely on the Emacs keybindings everywhere else.
There is a way to enable Emacs keybindings in all GTK apps on Linux, but it’s quite buggy in practice (many apps define keybindings that override or conflict with these), and I believe the feature is officially deprecated.