Is blockchain just a transition technology?

"WHAT happens when quantum computers become reality?" One of my favourite moments at a cryptocurrency seminar last year was when someone asked that question. The response was dead silence. After a long pause, the speaker said something to the tune of, "We will figure that out when we get there".

Let me explain. The entire premise of blockchain technology and the cryptocurrencies, non-fungible tokens (NFTs), and smart contracts that are built on it is that distributed ledgers are immensely secure and cannot be hacked with modern computers.

I am oversimplifying a bit, but in order for a transaction to be accepted by the blockchain, more than 50 per cent of the computers on the network that share the blockchain need to agree that the computer that claims to be the new owner of a crypto asset is indeed the legitimate owner. And the network only accepts claims that have a proof of work (PoW), which is essentially a massive multiplication exercise of several very large numbers. Again, I am oversimplifying here.