Type checking is analysis post facto and doesn’t account for dynamicism of classes.
The very ability to self modify an instance at any time or use __getattr__ makes it incredibly dynamic.
It also doesn’t account for every dependency having accurate type hints or any at all.
My mistake for not being clear. Obviously the python interpreter itself does not do any type checks.
It's sort if like how modern development with javascript is used with an external compiler of another language (typescript) that compiles a typed language into one without types.
An object can conform to a type in name only, but that’s not enough to tell you what methods or attributes exist on it at any given time.
In practice, your rebuttal almost never occurs. I believe these type checkers can detect monkey patching and trigger a type error or warning.
There are tons of libraries in many companies that use dynamic attribute lookups for efficiency reasons, when adapting to different data sources and the like. Or pass through lookups on nested objects. Or they’re dynamically looked up on bound libraries from other languages and frameworks.
And these type checkers cannot detect it. Python’s dictionary access is not guarded by the type checkers and neither is __getattr__.
If you’re making such wide sweeping statements you need to be more familiar with the subject matter.