Again, purely anecdotally, I've done similar things in both Typescript and Python, and I usually catch at least one silly type error in Typescript, but I rarely do in Python. That could be because the Python developers I was following were just so good, but I suspect it's more about the quality of the typecheckers. Typescript feels much better at finding errors in normal, idiomatic Javascript, whereas I feel that with Mypy, if I want the best results, I need to write code in a way that plays to its strengths.

I've been told that Pyright is better but I've not tried it out properly. But yeah, your experience largely matches with mine, for Python at least.