All of those left-pad libraries are a jest, it's trivial to do padding in those languages. I was wrong about Python and removing packages but on Nuget and Maven you can't, its not allowed.
I think it's worth noting that with Java at least, besides not allowing package removal, the namespace is tied to a unique identifier with ownership verification, so the cause of the left-pad fiasco (kik wanting his namespace) is extremely unlikely to happen in the first place.
If the curation process allows joke packages to pass through, it is completely useless. Looks like the only difference from npm is extra bureaucracy then.
And by date of project creation you can assume that others are parodies too: "LeftPad - Why should Node.js have all the fun?"