Recently I've come to a realization: Python types are unsustainable.
Don't get me wrong, Python's type system works. It works relatively well. So does mypy, the tool that does all the type checking. What I believe doesn't work well is the community.
The only problem is that this principal should be the same for Python. Why don't more people publish types for popular packages, or their own packages for that matter (yes, I'm included in that)? Really, the only extremely stable types that I know of are for the standard library!
Really, what needs to happen is more libraries need to add types and the documentation around writing types needs to be improved.
In the meantime, if you want reliable types, you might want to look into migrating to TypeScript.