> To me it seems that every alleged application of blockchain technology can be done by having a trusted organization maintaining a reliable database.
Congratulations, you have just discovered that every application of
a decentralized service can be implemented with an appropriate centralized
service without changing much of the protocol running on top of that service.
You do know that this is an obvious result, right?
Blockchain is the first cryptographic protocol for document timestamping that
does not need the trusted third party to run. This alone is a significant
technical success.