While the author enumerates the things they think you should do, I think it was very light on the _why_ you would want this setup. I think the argument of "you are doing it the old way" have been really ineffective at convincing people to do anything different, particularly around python tooling.
The official docs recommend doing many of the things the author cautions against or calls bad. https://packaging.python.org/en/latest/guides/distributing-p...