I’ll give you a couple examples of use cases for Blockchain technology that no other technology solves.

As currency:

• Payment system without content restrictions. You might say “But MasterCard said they’re not blocking it”, but they could, they could pressure Valve into removing other games, or something similar. Such a thing is impossible in Blockchain, there’s no single owner that can impose limits to what you can/can’t buy with it.
• International transactions without restrictions. We talked about how payment processors can stop transactions, banks and governments can do the same and while they use this power less often it’s still generally a pain in the ass to move money from one country to another.

As smart contracts:

• International car ownership deeds. In most countries car ownership has to be registered into the DMV equivalent, this means that moving a car from one country to another is problematic. A smart contract ledger would be an excellent solution to this, countries could use the ledger to transfer ownership and that transfer would be understood by any country that already uses the same ledger as a source of truth, without any of the countries having to trust in the systems built by the other countries.
• Something similar for phones could also include known stolen IMEI numbers that can be blocked internationally without any regulatory organization needing to trust one another or rely in a centralized controlling agency.