> Does reversibility actually matter anywhere outside of consumer merchant payments? Yes. For example, the stock markets can reverse a day's trading when it's

> Does reversibility actually matter anywhere outside of consumer merchant payments? Yes. For example, the stock markets can reverse a day's trading when it's decreed that there was a flash crash. And in contrast to smart contracts, all business contracts are in some sense reversible in extremis, in that you can go to court and consider the agreed upon intent if there was a typo in the paper, and resolve ambiguities after the fact based on precedent, instead of contract bugs resulting in all of your money getting stolen. I think we probably agree in that reversibility isn't important in _most cases_ (the mainline happy path), but I think it's really important when you do need it. > extend reversibility to other transaction types just so as to deploy it as a strategy to prevent open blockchains from becoming predominant That's not quite the claim I was getting at. Perhaps if I'd said "tighter control, for example being able to implement reversibility and right to deletion” it would be more precise. The core of my claim is not that those two are the killer features; the feature that will cause decentralized options to lose in the end is more generally the control that a centralized entity has over the end-to-end experience. Those two are just prominent examples of the kind of feature that are difficult or impossible to implement on the blockchain, which are actually strongly desirable for the market makers. Another example would be KYC, which is hard to solve at the protocol level. My overall prognostication here was really that the existing big players will pick and choose the bits of the blockchain systems that are actually innovative and useful (I'd highlight smart-contract execution engines and true API-based transaction instructions for example) while dropping the "distributed" bit to maintain tighter control and enable broader consumer adoption. Analogously to how Google et. al. have transitioned the internet from a distributed/federated "everyone hosts their own server and communicates over protocols" world to a centralized "everyone uses hosted services for everything" world. And consumers seem to prefer the latter, if the FAANG valuations are anything to measure this by!