Any reason why we can not edit payment information? For example on US money orders we can not edit address. Creating a whole new payment account all just because we moved across town or across the country like most Americans do diminishes our age, reputation and our trustworthyness by starting our account age to zero when we could have kept our account age accruing. The person didn’t change but the address did. That seems to be punishing.
Account age witness was primarily put to defend bank accounts from being cashed out quickly with Bisq when stolen.
It is simpler to threat all accounts similar when writing the software, so I assume that is the reason.
I am not sure what kind of benefit account age witness gives to US money orders, but as long as it is implemented, it only makes sense to hash all information unique to that account.