Well considering this is a realistic scenario for fallible humans, it’s still decent advice to keep your exploratory projects in python small to avoid ridiculous tech debt. It’s not quite as bad as with ruby, but it’s close.
Many languages make it problematic to keep code actually bug-free and maintainable, and Python and especially Ruby are problematic for that, while Java and Kotlin, but even C++ (with a strict style guide) are a lot nicer to work with at scale.
If you want to keep consistent APIs between modules, strict types and checked exceptions are very helpful, while with python one typo can lead to accesses being lost — which is why so many use slots nowadays, and TypedPython, and annotations. But if I do that, I might as well use Java or Kotlin, and get a better IDE.
Compared to unit tests, strict and static types are faster, compared to no testing, static types are safer.