Are you aware that when you trade goods, services or fiat currencies for Bitcoin, you actually bought nothing. In other words, by buying Bitcoin you sold the ownership of something and bought the ownership of nothing. Bitcoin is the first time in human history that people voluntarily give up something to become the owners of absolutely and literally nothing.
And what happens when someone pays for your goods with a card? A third party payment processor logs the transaction on their servers and messages your bank that it took place. You don't get any physical item, you don't get money. Only thing that changes are some digits on a privately own mainframe. How is that different from the blockchain? Let's start by saying that blockchain cannot be changed or erased, but the mainframe can. Blockchain can't go bankrupt, but both the payment processor and your bank can. Even your country that issues cash (that you aren't getting for that transaction because it was digital) can go bankrupt.
I'll take my coins, thank you.