Poetry...not so much. requirements.txt is good enough for me most of the time.
unless you're on some flavor of ubuntu where they aren't bundled with the system python. then you're in python packaging hell.
Node avoids the need for a "venv" because each project has its own "venv", which if you have a 700mb pytorch install, ick.
Rust/go don't deal with .so files to the extent python does, so cargo/godep have an easier time. Python is a C abstraction layer.
So like, I'm not sure how much less you need than "package manager" and "env manager".
Maybe you misspoke, but whether you are left impressed or not is your opinion. What is factual is that these tools are the ecosystem's default tools for their jobs, and have been for a long time. I have relied on them operating multiple production codebases over the course of a decade.
I think you need to elaborate on what about that doesn't suit your needs rather than that they don't impress you for some vague, unspecified and potentially arbitrary reason.
To answer your question, why do they impress me? They get out of my way, they work, and they don't require me to do anything but have a system version of Python installed. With them, I get reasonably sane package management and environment isolation without headaches. That's enough for me.
I don't think impressing you was one of their design goals... If you claim different tools like poetry are better, then the burden of proof is on you
What things do you want to do that pip and venv can't (or make it difficult) to do?
What features does Poetry and Pyenv provide that these don't?