Hello,
Just adding to this, I vaguely remember some earlier comments or discussion on installing Python-based GRASS add-ons as Python packages, i.e., via pip. The itzi add-on is the main (only?) example that I can think of that does this.
In terms of a possible justification, using the GitHub API, I summarized what languages are used in the GRASS add-ons directory based on (a) number of files; (b) total size (in bytes); and most relevant, (c) the number of add-ons that use a particular language.
Almost 70% of add-ons use Python and (not shown in the plots) most of these exclusively use either Python or C. Only a handful of add-ons like r.futures use both.
Not really sure what the implications would be (particularly in terms of testing). Some positives would be that Python dependency management could leveraged, so that add-ons that require pandas, scikit-learn, numba, etc., could be managed without the user needing to manually install the correct versions. I could imagine once GRASS is available via conda, installing add-ons via pip/conda could be a nice mechanism.