Coming at this from an accessibility… is there any reason the tab, arrow, scape, escape and enter keys would not suffice?
Is it about efficiency? Are Linux GUI apps not expected to be keyboard-only accessible by default?
Yes, but keyboard-only is not the "top priority", now that everyone has a mouse, and everyone uses a GUI.
I'm on KDE Plasma. Dolphin is the file manager. F2 to rename. No shortcut to move selected files to a new folder, so I use the arrow keys, and that little key next to right Ctrl that I can guarantee you've never pressed. Eventually, the workflow breaks (when I have to go back to the web browser), if it wasn't already clear that this isn't how Dolphin was designed to be used.
I'm not necessarily trying to outright kill the mouse, but I'd like to keep to a workflow going when I'm using it--hence, why I'd need a fundamentally different setup. If I'm keyboard only for a portion of some task, I'd like to keep to that for other portions, if at all possible. It's just faster and more consistent.
So, I've come for recommendations on software. I've already seen quite a few suggestions that I've never heard of, and I'll be trying a lot of it.
OK, tiling window managers are neat and so are TUIs, but web pages are also supposed to work with keyboard only. On Windows, F6 will jump between different panels in an application - give that a try.
The key you’re talking about is the menu key, by the way.
Using a modern OS and the modern web with the keyboard only is essentially a solved problem, not only motivated by efficiency, but also to allow access to people with motor disabilities.
KDE has a huge amount amount of configurable keyboard shortcuts, even many that are not assigned by default. Check out the keyboard shortcuts settings in each app, and in KDE Plasma Settings app.
For moving selected files in Dolphin (and any other file browser) I've always just used Ctrl+X Ctrl+V.
(Btw sounds like you're talking about the "context menu" button, and it's my personal pet peeve that this button is missing from many modern keyboards and laptops. On older Windows you used to be able to do Shift+F10 to get the context menu , but that doesn't work anymore so my main use for the mouse is right-clicking..)
Lot of great recommendations so far, but I will mention some of my favourites in case they were missed in the other comments: hyprland for a Wayland compositor / window manager, so you can easily set up keybinds for whatever you want, rofi for launching programs (and much more, I even made rofi-games so I can launch all my games from one place), and yazi for the file manager (use a lot of TUIs in general though).
You CAN go more extreme with the no mouse journey by using something like qutebrowser as your browser but I just use Firefox/librewolf with vimium c and find that's good enough for me.
You can go a long way with a touchscreen, but the most annoying thing for me is that in Terminal, using touchscreen selects text instead of scrolling. Other than that, mouse is hardly necessary.
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