whenever you need these three things together: decentralization, secure, and auditable data. Could be the cases when we do not want to give the authority of the data to a central resource. Like, what if all educational institutions host blockchain nodes to store educational records of their students. There can be similar use-cases but most of the noise is due to a buzz word and companies want to cash it.
What if there is no more blockchain technology tomorrow morning, will your project survive? If your answer is YES then you might need to rethink about it.
This is like asking, "What if there is no more database technology tomorrow morning, will your project survive?"
I am using blockchain just as a distributed, federated and tamperproof database. Nothing else.
You could ask "What if cryptocurrencies do not exists tomorrow?" That is a valid question. But that I don't think applies as easily to database technologies.
