I think you're underestimating the current state of the Python type system. With Python 3.12 and pyright or mypy in strict mode, it's very reliable, and it makes those kinds of tests unnecessary. This requires you to fully buy into the idea, though, with 100% of your codebase statically typed and using only typed libraries, unless you're comfortable writing wrappers.

It's not Rust-level, but I'd argue it's better than C or Go's type systems.