They don’t need to use semantic versioning. I doubt coreutils itself uses it, though I admit I haven’t checked. Actually I think semantic versioning is less popular in practice than it looks like.

For a set of tools to that completely replaces another one, announcing a 1.0 version would be a message that the developers think the project has actually reached its initial goals. “0.2” does not.

Rust is great, but might it be a bit premature to replace the venerable coreutils with a project boasting version number 0.2, which I imagine reflects its author’s view on its maturity?

Yeah, with mpv you can even hold the jump 10/60 sec forward/backward button pressed and the frames just fly in the screen. Vlc seeking is really slow in comparison.