Oh no, the Niri keyboard shortcuts for Noctalia would definitely not work if you removed it, or if you aren't running it. 😄 And vice versa for DMS.
That's the beauty of Niri's include directive, that you can include different config files depending on which environment you are in. Very handy.
I have one for Noctalia bindings e.g.
I guess if you are used to nix already and can work efficiently with it, it's a net gain of plus minus zero. I guess that's why I don't use it. I have to learn something fairly complicated in order to be able to do something I can already do equally efficiently. 😅