Doesn't matter. That's what the majority of people are using; so if you want the marketplace to actually be able to serve people, and get them to actually buy stuff, you need to support them.
Perhaps the idea of a decentralized marketplace is a bad idea? What benefit does this actually give me in my everyday life where I don’t need to buy toilet paper anonymously?
How do credit/debit cards satisfy the proposition of a decentralized marketplace?