My belief is that it is a bit harder for IDE to determine which structs and interfaces should be changed, due to Go using "duck typing" (or more correctly called structural type system).
The mypy uses nominal type system (similar to what you're used in C++, Java etc) by default but it also allows to implement duck typing in places where you need it through Protocols.
Overall the type system is more powerful than the one in Go[1], it even includes generics =)
Slightly unrelated, but when working with Go, I feel like the type always gets in my way. Go typing (similarly to Python) is strict and that's great, but Go trying to be low level it implements different sizes (int, int8, int16, int32, int64, uint, uint8, uint16, uint32, uint64, float32, float64) it doesn't do implicit conversion like C, but it also doesn't implement generics, and stdlib only implements functions for one of the type. That means if you use anything else than int, int64, float64 in your program you'll be in a lot of pain and will be constantly casting the types back and forth.
Having programmed in Python (with type annotations) and now at my current job in Go, I love Python.