> They eliminate inheritance, replacing it with interfaces. Exposing the objects for what they really are, structs with functions attached, makes this strategy easier.
I don't see how this is not already achievable in Java or C#. No one is forcing you to use inheritance. And when you really need it, it's there for you to use instead of jumping through hoops.
That's basically true. Languages that use interfaces with structural typing are significantly easier to work with though. You can "implement" an interface implicitly by just having matching fields
This means you can't use interfaces as tags, which is a very important feature (e.g. see how it's used in Rust). It also means that you have several different types implementing your interface "by coincidence", making it difficult to use an IDE to find out the types of interest, not to mention what sorts of bugs might result because of this.
There are better solutions like what Kotlin and Scala use (and potentially C# in a future version).
I don't see how this is not already achievable in Java or C#. No one is forcing you to use inheritance. And when you really need it, it's there for you to use instead of jumping through hoops.