Absolute immutability is kind of a terrible property for a financial system though, cos it completely ignores the fact that mistakes and fraud happen and you need a way to forcefully recover funds other than “lol sucks to be you I guess”.
The one actually genuinely useful application for this kind of technology that anyone has come up with is Certificate Transparency, but crypto people don’t get excited about it cos it’s not possible to make money from it.
You can revert transactions with immutable storage. For example git can do revert-commits.
Yes. Clawback might be executed by having some entity or system of trust that is able to reverse a transaction by creating and posting the opposite of the faulty transaction. This is not built in to the current BTC.
Reverts work because users have equal write access to all the data. You can mess things up in the codebase, and even if you die of a heart attack 10m later, my revert is just as valid as your commit.
It’s not really the same when every user has “sovereignty” over their address in the ledger. A bad actor has to consent to pushing a revert transaction onto the chain, or they have to consent to using a blockchain system where 3rd-party reversion is possible (which exists on some systems, but also defeats the concept of true sovereignty over your address).
You can implement clawback while still having an immutable blockchain. The transaction will always stay on the blockchain, but the funds can be recovered
