> implicit access to interface members isn't a thing, you need to say that "x is this interface type" or cast.

If the compiler already knows that it implements interface X Y and Z, it seems unnecessary to require it (unless those interfaces have conflicting names, in which case you would have to be explicit due to ambiguity).

I feel like many languages are walking away from being so explicit, in particular I've noticed C# becoming more implicit over the years.