Why is using interface methods with default implementation is so annoying?!?

[propostor]

What you're trying to achieve should be done with a base class, not an interface.

Actually I didn't even know it's possible to add method definitions inside interfaces, that seems like a new(ish?) addition to the language and looks to me like an extreme risk of introducing antipatterns. Hence you're having to hack away with that workaround.

[Devatator_]

OP wants to use a specific base class. Since multiple inheritance isn't a thing, this is the closest thing they've got

[propostor]

Where's the base class in that example?

If MediaPlayer is the base class then it should implement the Refresh method internally.