(1) all of these can essentially require transparency + encryption (i.e. git + signatures), not the whole blockchain,
(2) hence can be had without the huge energy losses (that come from many nodes (re-)computing the same result over and over, and
(3) centralisation is a feature most people want, because it helps resolve conflicts (à la Vitalik's centralised resolution of the DAO conflict).
That's just empirically not true. You need to timestamp transactions in a BFT way for all those examples. No way around it.
> hence can be had without the huge energy losses (that come from many nodes (re-)computing the same result over and over, and
You can get this with Proof of Stake. But you do need a BFT timestamping mechanism.
> centralisation is a feature most people want, because it helps resolve conflicts (à la Vitalik's centralised resolution of the DAO conflict).
Citation needed. Centralization has upsides and downsides. It will take time to figure out how to do decentralization well.
No, for most things what you really need is a happens before relationship. Git does that better, since it supports multiple timelines (branches) that can be resolved (merged) cleanly if there are no conflicts (double spends).
What about when there are, though?
How long do we have to wait to find how to do decentralization well? It's been 10 years now and we're still asking the same question.
I guess you could have a 3rd party that has to verify everything ( government ) but then you are basically back to just doing it with a paper deed at the courthouse.
Right now, getting into the 'trusted financial institution' list is extremely difficult. It's a slow, incremental process that takes decades of good behavior and careful stewardship. Part of the reason it's so difficult and so heavily regulated is because of how much trust we place in these institutions. If we did not have to trust them so much, it would be easier to become one. It would have less need for regulation. Incumbents would be weaker, and the industry as a whole would therefore be healthier. This is sort of an abstract point, but I think it's the truest sense in which blockchain may change the world: by commoditizing trust.
a really neat case for this would be lost items. if each cellphone had its IMEI and your keypair associated you could prove you owned something lost. or if found someone could look you up to return it. you could buy a game or software once and never have to worry about a serial key.
Here are some use cases that I think are potentially legit: