Well, it is also possible to send money to the wrong account number by bank transfer. In that case the banks also generally say that they cannot do anything about it.
I don't think this is true. I think usually an obvious error like a large sum sent to an incorrect account is reversible. Though certain specific transactions such as wires are harder to recover than others such as intrabank transfers.
Yes, which you go through a governance system (our legal system) to recover it. Crypto governance works similarly where it exists in varied forms (e.g. replace the contract or hard fork).
It’s not mature yet but the parallels exist and crypto’s will continue to develop.
(The others are wrong amount and duplicate transactions.)