Yes, but this is about crypto and blockchain. Cryptocurrency is a singular use case of blockchain. In a world economy built on ledgers and supply chains of both goods and information blockchain technology has legitimate applications. Moreover, the move to proof of stake rather than proof of work cuts energy costs to the equivalent of refreshing a web page 3 or 4 times (in the case of Ethereum 2)

Digital signatures and electronic signatures are somewhat different from each other. An electronic signature can be an image or a check mark or even a recorded sound whereas a digital signature is tied to a certification authority attesting to the validity of the signer (or something like that). Standards for digital signatures vary by country but my understanding is that updates are underway to cover blockchain signatures (NIST in the US and EIDAS in the EU)

Sovereign identity is one function- you can attach identity to data on the ledger and claim IP rights as well as track and “own” rights to data files as they are iterated or updated. It also has a digital signature function that allows you to legally sign data as a contract.