The downside of course is that Python is very dynamic - so IDEs are of relatively limited use.
I am surprised to hear you say that with "PyCharm" being the first word in your comment. We have had very good experiences with PyCharm + reStructuredText annotations to help it when the return type or arg type is not inferable. Just like its IJ friend, PyCharm has caught quite a few bugs and helps the team edit Python and not text.
PyCharm's usage is not optional on my team; we tried the "use whatever text editor you want" approach and it turns out that people are not as good at memorizing the type signatures of a complicated codebase as computers are.
It basically boils down to minimalism (in general) with an emphasis on minimalist code instead of minimalist UX/UI (whenever the two conflict).