In the light of the various data scandals (cambridge analytica and the like) I think that the argument may be valid technically, but absolutely no user cares. So I wonder what a good argument for blockchain actually is.

Thus far, two things strike me:

1. digital scarcity: I can send you something and prove that I don't have it anymore and 2. atomic transactions: a value creating process can be tied together with its payment, thus eliminating the payment process as a secondary process altogether.

(This is a very brief digest, a more thorough line of thought is here: https://medium.com/swlh/trust-in-blockchain-close-but-no-cigar-d17079459cdd)

What is Blockchain's killer feature in your view?