Browsing code, underlying library imports and associated code, type hinting, error checking, etc., are so vastly superior in something like Pycharm that it is really hard to see why one would give it all up to work in a Notebook unless they never matured their skillsets to see the benefits afforded by a more powerful IDE? I think notebooks can have their place and are certainly great for documenting things with a mix of Markdown, LaTeX and code, as well as for tutorials that someone else can directly execute. And some of the interactive widgets can also make for nice demos when needed.
Notebooks also make for poor habits often times and as you mentioned, having data scientists and ML engineers write code as modules or commit them via pull-requests helps them grow into being better software engineers which in my experience is almost a necessity to be a good and effective data scientist and ML engineer.
And lastly, version controlling notebooks is such a nightmare. Nor is it conducive to code reviews.