The blockchain might not be the best solution for most of those problems especially those that cannot be solved by traditional pgp/gpg signatures and certificat

The blockchain might not be the best solution for most of those problems especially those that cannot be solved by traditional pgp/gpg signatures and certificates, and for those where traditional signatures work the blockchain add mostly complexity. The obvious real world use case of using blockchain to track shipping containers across modes of transport(and companies) failed late 2022 when the tradelens project was terminated(https://www.maersk.com/news/articles/2022/11/29/maersk-and-ibm-to-discontinue-tradelens https://www.maersk.com/news/articles/2022/11/29/maersk-and-i...) after at least 4 years of work by the shipping industry's largest players. And that's essentially the case everywhere people are trying to get real value from blockchain based solutions.