Is there a good explanation as to why python-level tools like nox and poetry seem to avoid integrating with pyenv?

Pyenv seems to be the defacto python version manager, and Pipenv seemed to integrate well with it. Why has the python tooling community moved away from it?

pyenv is really slow. It'll increase the time it takes to run `python` by a ton. For me it makes `python -V` take ~120ms but without pyenv it only takes ~13ms.

I wrote an alternative that has 0 overhead called rtx. https://github.com/jdxcode/rtx