From a practical perspective blockchain can be regarded as a decentralized highly available and reliable communication channel between different actors. It is served at the moment rather to transfer value between the different actors without the primary goal to transfer information, however applications could also be imagined where instead besides of value rather information is exchanged. In this sense applications that should be based on a global decentralized event bus can be also imagined based on blockchain.
Certainly, performance is still an issue, with the current speed of bitcoin or ethereum such an event bus can not be considered to be too performant. However with technologies as Hashgraph such an applications might be easily imagined. With that the question is which use-cases could be considered to be implemented on a distributed ledger technology that focus not only on value exchange, but somehow on information and value exchange ?