This is like saying that anything not directly querying the root DNS nodes is not really using DNS. DNS responses are cached from said DNS nodes, and served by the myriad of DNS servers.

In a similar sense, blockchains with layer 2 scaling, result in all address balances being stored in the central blockchain, while people can transact with each other directly and instantly in a zero-trust, cryptographically secure manner. When either party in the transaction is "done", one of the parties will commit the address balances to the blockchain for the world to see. (The only model that makes sense, and actually allows for scaling, is a hub-and-spoke model, where everyone connects to a "node", much like with DNS, and lets the node handle the routing. This way users could keep accounts open while transacting with many different people / businesses.)

StarkEx is a blockchain, it’s just a blockchain that gets its security from another blockchain and has configurations for how to handle data availability.