macOS is my favourite operating system. Finder in column view with arrow keys to navigate, combined with space for file preview, is incredibly fast and intuitive. Trackpad integration also results in less hand movement. I'm building a Linux (Bazzite) desktop, though, and I've set my sights on the stars.
nnn looks to be an incredible file manager, and was a great recommendation. It looks even more capable than Finder, albeit without scrolling/zooming previews, thanks to macOS having unmatched trackpad functionality. Not to mention Spotlight, which makes opening apps trivial--especially with Alfred available as well. I want to go beyond mere file management, though.
File managenent, browsing, gaming, everything. Just how much can you configure a Linux system to eliminate mouse usage? Shortcut guides welcome (I already know the major ones). I also have a keen interest in tiling window managers, but I've not delved that deep yet. I don't know how to set one up.
Even better, after your machine boots up, press ctrl+alt+F(3-6) to access TTY sessions and then there is no mouse at all. Plenty of TUI apps work just fine here too.
I was mostly being tongue in cheek, but I think it might be possible to launch steam in big picture mode, rendered by Gamescope, from the TUI. No DE required.
Unfortunately there is often a use case for mouse that is hardly doable without, such as nondestructive video editing or image editing. I even use the mouse in Vim. Why is there this obsession not to touch the mouse??
My point is, it depends on the workflow and the tools. Try editing complex images with keyboard alone with GIMP or Inkscape. I'm a Vim user and used tiling window managers for years, so I know exactly what you mean with keyboard centric workflow being productive. But sometimes ignoring the mouse can make the workflow harder, not easier. Off course it always depends on what you actually do.
Edit: Guess I answered my ... question (even though it wasn't a question). Never mind.
It sounds like OP wants a "mouseless except for gaming" setup, no mention of image or video editing. Sounds like the slippery slope into ergo-mechs tbh