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.
(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).