I honestly think this is a factor of prior experience. When I started using Rust my background was in OOP languages, so I also went through the exercise of fitting trait pegs into a class shaped holes and it was painful. But this doesn't mean that traits and ADTs and how they interact is harder to learn or understand than Objects with its inheritance, polymorphism, encapsulation and abstraction concepts, it just means that if you already know those, you will have to learn new concepts to learn Rust, which can be surprising if you aren't told about it ahead of time, particularly when you already know several languages that don't use traits.