One useful thing that hk appears to currently lack compared to competition is content based file matching, it only supports filename globbing.

This is most useful for script files written in different languages lacking filename extension, but sometimes it would be convenient for other cases as well. One can always write ~exact-match globs and make use of excludes to cover applicable filenames, but it's inconvenient at times.

Lefthook recently added media type based matching which I think is nice (although it IMHO unnecessarily limits matching to some allowlisted types): https://lefthook.dev/configuration/file_types.html, uses https://github.com/gabriel-vasile/mimetype under the hood.

pre-commit has a similar feature with bespoke file type names rather than media types: https://pre-commit.com/#filtering-files-with-types