I remember someone already proposed this some time ago as part of the language

That is called “type classes” :)

No, I mean extend each data class implicitly from interface with component1..N method and have Component1, Component2 interfaces

As I know the return type of componentN() for each data class is depending on the type of its corresponding property. How can we have a common interface of that?

interface Component1<A>

,

interface Component2<A, B> : Component<A>

etc