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.
Guess I'm forced to learn Emacs/Vim/similar.
As others have suggested, getting more familiar with the terminal and using a tiling window manager will help a lot. And yeah it's a great idea to learn Vim or other advanced terminal editors. I use Helix+Zellij for development, Vim for system configuration, and i3 or Sway for GUI stuff. Also check out w3m for simple web searches.
If you want to get rid of the mouse entirely, you can also try using a programmable keyboard with mouse support. I don't use a physical mouse anymore because I do most things in the terminal, and when I do need a mouse I just use my keyboard to move the cursor. For super mouse-heavy tasks like image editing it's good to keep one around or use a Wacom tablet