Earlier quoted context omitted.
I have to deal with many of these regularly, yes. But more generally, I'm expressing a desire for fewer ecosystem-specific package managers and more ecosystem-agnostic package managers.
Right, but why? Generalization isn't free, and there doesn't seem to be any real benefit here. This sounds to me like arguing that there should be one programming language, or one version control system, or one declarative sysadmin automation language. I think that the cost in complexity for one Uber package manager is greater than the waste in duplication from many smaller, more focused ones.
Because, among many other reasons, I work with a lot of projects that aren't written in just one programming language or use one type of environment. It's not just "I don't want to use five package managers for five different projects in five ecosystems", it's "I don't want to bridge between five package managers for one project that touches five ecosystems". (Or a project in one ecosystem with dependencies from another...)