It caught my attention when you mentioned that some of the package managers are called from inside the language and others from outside. Do you think there are cases when this might be a major factor for which language to choose for a project?
I can't really imagine that it's ever a big factor in your decision. People may have a preference, I prefer the in-language approach, but compiled languages like Rust/C++/etc don't even use a REPL, so then keeping it outside makes sense.