Would mypy with pydantic be a good combination or do they overlap?
Pydantic overlaps with mypy in the sense that it provides a mypy plugin, but otherwise it's just like any other Python library.
Those other things you mentioned aren't relevant to tooling. They're distributions, libraries, and applications. But note that Conda's existence was basically due to the fact of Python's tooling being poor.
I began in that world view. The C/C++/Java/DotNet everything must have a standard, a fixation on a singular consensus. That's not how things work in the open source world of Python, javascript, rust, etc. Will there be gravitation towards a paradigm? sure, until such time that a new one emerges.
If you looked at Python in the 2.5 days and looked at Python today - You cannot argue the tooling has gotten better.
That doesn't surprise me.
I do what you mentioned with F# in Polyglot Notebooks (which support several languages in the same notebook) and Elixir in Livebook all the time, both of which are superior notebook implementations to the outdated Python Jupyter notebooks.
My worldview is not driven by comparing Python to C#, Java, C++, and other such ilk.