There are two types of blockchain
There is the truly open one (proof of work and non-authenticated) i.e. bitcoin. The exciting thing about this version is that it (supposedly) allow untrusted participants to agree that something happened. The fact it does it by a chain of hashblocks is completely immaterial to the average person. The fact that money gets stolen from this blockchain on a reasonably regular basis a) scares me b) never makes the main news!
The second are more closed blockchains (often proof of stake and authenticated). I still get lost as to what's so special about an authenticated blockchain and why it's better than a distributed/shared database. As soon as I know who someone is then why do I need consensus? I trust them don't I ? I don't get how we don't get contention - I must use transactions ?
Most of the business focussed (think maersk) are run on the latter type of blockchain and therefore aren't costing the earth in electricity to run (well, not much more than any of the rest of our day-to-day computing tasks do.). Also, I believe that the banks are using the shared ledgers to share information like codes - that don't change a lot and aren't public per se. Again - why not a DB with an API fronting it - I'm lost. I guess they like the idea of saying they literally have a ledger technology holding their ledger of codes. Sort of makes sense, but, to me, there's other tech that can (and presumably did?) do it. I'm betting that blockchain will be "just another tech" sometime in the not too distant future that has a niche or two - the rest of us will just use DBs.