Bank transactions are not irreversible. Have you never received a refund?
A bank can revert your transactions. They can also retain it until they verify if it is "clean" or not. They can revert and even give you a negative balance. Those things are not possible with bitcoin.
In my account, if I want to send money to an account I've never sent money to before my bank will give me a pop-up message telling me to make sure the details are correct because the transaction cannot be reversed.
I've only ever received a refund when there was a failed transaction. If I make a transfer and the beneficiary account didn't receive the money sent, but I was debited then I can receive a refund, but once that money has been successfully transferred to the beneficiary account you can't get a refund.
I don't know how things are where you're from but where I'm from if you mistakingly send money to the wrong account, you can't get it back unless the owner of the account transfers it back. I have not heard of any case where somebody reports this kind of case to the bank and the bank just withdraws the money and sends it back without the consent of the owner of the account.
Most times people return these kinds of money because they'll be easy to track since the bank has all your information.
It depends on who. What is not perfect to you may be perfect to someone else. Irreversibility can be a feature, you may not see this until you can relate how it favored you.
If a thing was perfect then it would be perfect for everybody and in all areas. It would have no disadvantages or weaknesses of any form. It is based on this that I say there is nothing that is completely perfect in this life.