Guid package generates guids/uuids. Your linked package generates variable length strings. These are different usecases (oh, and your benchmarks are inferior to https://github.com/sdrapkin/randstring). Nothing to argue about.
You have a 16byte random string. Thats great. But it is not a UUID.
[0] https://www.rfc-editor.org/rfc/rfc9562.html
> The UUID format is 16 octets (128 bits) in size; the variant bits in conjunction with the version bits described in the next sections determine finer structure.
If you want "more choice" - use a name unbound by a tradition old enough to drink.
And in most use cases where I'd need a UUID, I'd usually want the string representation of it.