And miss the chance to rewrite it in Rust or Go? :)

Jest aside, it's much easier to write a small tool from scratch, than to contribute to coreutils, where this kind of improvement is likely to be rejected, for various arguably valid reasons.

Besides, having alternatives is healthy for the Linux ecosystem, and writing something from scratch is a good learning experience.

Making a new tool means you can break backwards compatibility.

Better is also subjective.