Similar to your first point, types also allow an IDE to inform user about what values can be used for a function or class argument. I can't say that typing bug

Similar to your first point, types also allow an IDE to inform user about what values can be used for a function or class argument. I can't say that typing bugs occurred very often in released code I wrote before type annotations, but it was not uncommon to encounter them when testing code I had just written (where they usually just caused an exception early on in the program's lifecycle).