After some research. (And still as yet unable to locate "The Pipx people".)
Like most projects these days, it'd be via github:
Could also be a mint problem, FWIW. Could also be residue packages on your system that is causing pipx (really pip, under the covers) to choke while enumerating them.
Then removed/purged python3-venv and python3-pip
That also removed pipx.
Yeah, removing and reinstalling pip/pipx is not going to solve a problem with stuff in your ~/.local, if that's indeed what/where the problem is.
Looking at the structure of the .whl file, it "seems" to be a simple compressed archive of a folder structure that contains the application.
So, how to install that manually, and invoke it correctly?
Or, how to install from sources?
The source is the .tar.gz file on the archive site. You're more than welcome to try to get it running by building a venv, installing all your own dependencies into it and installing it manually into that venv.
--Dan