what it has is "type hints" which is way to have richer integration with type checkers and your IDE, but will never offer more than that as is
Python is strongly typed and it's interpreter is type aware of it's variables, so you're probably overreaching with that statement. Because Python's internals are type aware, it's how folks are able to create type checkers like mypy and pydantic both written in Python. Maybe you're thinking about TS/JSDoc, which is just window dressing for IDEs to display hints as you described?
https://stackoverflow.com/questions/2690544/what-is-the-diff...
https://wiki.python.org/moin/Why%20is%20Python%20a%20dynamic...
https://github.com/mypyc/mypyc
You can compile python to c. Right now. Compatibility with extensions still needs a bit of work. But you can write extremely strict python.
That's without getting into things like cython.
def plus(x, y):
return x+y
Python types are strictly specified, but also dynamic. You don't need static types in order to have strict types, and indeed just because you've got static types (in TS, for example) doesn't mean you have strict types.
A Python string is always a string, nothing is going to magically turn it into a number just because it's a string representation of a number. The same (sadly) can't be said of Javascript.
The plus function you wrote is not more confusing than any generic function in a language that supports that.
You just did tell us what it does by looking at it, for the 90% case at least. It might be useful to throw two lists in there as well. Throw a custom object in there? It will work if you planned ahead with dunder add and radd. If not fix, implement, or roll back.
Indeed assuming it adds two things is correct, and knowing that concatenation is how Python defines adding strings is important for using the language in the intended way.