His points about blockchain are compelling but I disagree with “blockchain/decentralisation” part. Blockchain is a decentralised ideal, but so is BitTorrent, so is Tor, and so on, to some significant extent. To say that decentralisation failed because blockchain failed ignores all the other technologies which are serving people well.
I think the distinction between “decentralised” (i.e. federated) and “distributed” is important (as decentralised is often used as an umbrella term to cover both).[0] There are tons of federated projects out there from Matrix to Mastodon, and there are initiatives to make federated networks more decentralised (such as the integration of Kademlia DHT in BitTorrent).
No need for pessimism I think. :)
[0]: https://www.researchgate.net/profile/Jason_Hoelscher/publica...
Also, the blockchain has introduced (AFAIK) the idea of using append-only databases to build decentralized applications, and this is currently used in very interesting new techs which have nothing to do with currencies or economics (like secure-scuttlebutt). The "dweb" is becoming a thing, IMO.
Before blockchain was a thing much less a hyped one cloud computing used it and before that some databases practiced 'tombstones' for databases. The easiest way to maintain absolute consistency has been known to be not really deleting things but marking them as 'deleted' and leaving them to be ignored by default until consistency can be achieved. That was the approach when cloud computing dawned to make things scaleable and avoid the bottlenecks and load-balancing server overhead.
Transaction based databases are logically equivalent to an append only database. If you have a list of transactions that add up to the same resulting database state - with the option of more versatility if you don't constrain things to be operational order insensitive.
It makes me realize that git is probably some kind of append-only database too (and used for decentralization too).
I guess I can still thank blockchain for having introduced the idea to me.