First gives a short answer. Other poster is not satisied with that. Then apologizes and gives a longer more informative answer.
Then gets downvoted to hell.
I wonder if next time, you will still give a longer answer, or just not bother anymore.
Welcome to the club.
So if you want use cases, you can look it up on the net. And if you want something to bash on, you won't get it from me.
Energy cost can be very low when using Proof of Stake. For example a 7000 transactions per second network could run on the energy of a single windmill: https://www.reddit.com/r/nanocurrency/comments/7ucw1a/the_en...
And for use cases, the second hand car industry is ready for disruption. You could say all blockchain use cases can be also handled by a central database. But this has failed miserably in the car industry. There are plenty of companies trying to log metadata, and as a result none of them have the complete picture. Even data aggregator companies are not able to properly bundle it.
Blockchain could offer a very good trustless solution, where you could log a cars history, and a second hand buyer could consult it.
Therefore, big names are entering this space, and I'm confident we will see blockchain solutions in that market soon.
This is only 1 example: https://www.ledgerinsights.com/mercedes-benz-blockchain-used...
The DHL website also has a nice explanation on their use cases https://www.dhl.com/global-en/home/insights-and-innovation/i...
I know that was not your claim, but it could be read as such and many people think that way of crypto.
Not saying that will not change in the future.
When I'm interested to get a feel for the range of crypto projects with significant traction, I sometimes start here: https://snapshot.org/#/
But it's hard to point to a single place. There are many worlds in crypto. Twitter is a portal to some. One must go on an adventure.
Here's something a friend works on: https://www.regen.network/
For me, crypto enables experimenting with new kinds of corporate structures. That's what I work on. I think we have a decent shot at replacing the current model—basically psychopathic projections of sick humans minds—with something that won't destroy Earth.
It's very hard to do that without programmable money.