To come = datang To arrive = sampai; tiba
Yes, both are interchangeable in certain context, but they aren't synonyms.
They aren't interchangeable as follows: Will you come to my party? = Apakah kamu akan datang ke pestaku?
You can't use "sampai" or "tiba" for this context.
They come and got rejected by duolingo push for losing their streak, so they go.