How would this feature be useful?
We have homebrew (which is slowly getting better) on the macOS side of things. I think adding a snap package would cover almost all the major linux distributions these days. https://snapcraft.io/

Additionally a scoop package should make it much easier to install pipx on Windows: https://scoop.sh/

Describe the solution you'd like
Easy system installations of pipx:

brew install pipx
snap install pipx
scoop install pipx

Describe alternatives you've considered
As you obviously know from creating pipx, pip is not an ideal installation method for system wide utilities. I think creating system packages for pipx on all three major platforms will help this tool grow.