I don't get your point or what it has to do with the "pythonic" suggestion that you don't check early for incorrect state/arguments?

Any language, including Python, which supports the concept of a class will allow you to write a class called IImplementsFactoryAbstractMethodThingVirtual. And none of Java, C++, Python, Typescript, CLISP, etc. prevent you from building or designing an overly complex class model.

It has nothing to do with ensuring a particular argument to a function or method is of the expected type, which was my point - the "pythonic" way is to NOT check.

I also do not understand your example of Typescript. Compared to the last time I worked on a Javascript code-base, recently having to work with a Typescript code-base was a joy including reading library code. Stripping out the types gives you Javascript - surely you are not claiming that it makes it easier to read libraries with the type signatures removed?

Whether a library is complex or not is completely orthogonal. Doing it regularly, navigating the source of an overly-complex Python library is no fun either.