It is not when mempool is congested, it is when transaction has not been confirmed that you can double-spend the coin, but there is higher chance for low fee transactions to be confirmed fast when mempool is not congested.
Right, I know about that. When the mempool have a spike in transactions that can cause congested for low-fee transactions, then the fees required to get confirmation faster will also increase. RBF allows for bump fees
[pay higher fees while the transaction is still in 0conf state].Also bitcoin transaction should be confirmed faster than cross border fiat transactions if appropriate fee is used in accordance to mempool estimation that could get transaction confirm earlier. No third party needed, all can be done at your comfort in your home or wherever you are.
That is one of the advantages of bitcoin over other financial systems. Choose your own fees, security, transparency, increase financial privacy and more.
They are, though. When you transfer fiat electronically, the vast majority of the time all that changes immediately are the numbers you see on the screen, as your entry in the central database is updated, and no money actually moves hands for several business days. And even once the money has moved hands, it can be reversed or clawed back for months after. Bitcoin transaction can be completely finalized in 10 minutes.
Maybe you are right but only if the recipient keeps it in the bank account without spending it or withdrawing it. I once received some money in a bank account without knowing who the sender was, only a few minutes the bank withdrew the money and my balance returned to normal. They really can do it, but with bitcoin once a transaction is confirmed, it can no longer be undone unless the recipient is willing to send it back.