WoW! I finally found a way to show the differentiation in speed between JSON::Any and static types

That’s not necessarily bad. It could just be a sign that it’s feature complete (for now) and well implemented. Might as well be cause that it’s not much in use, I don’t know. But it’s still maintained. And I’m pretty sure the author is using it in some projects.
So, while there was no release recently, I suppose its still usable.