If you say "when I sent this business my money or goods in the past, they always send me goods or money, so I trust them" you are vulnerable to exit scams and rug pulling. One of Dan Davies' examples is a darkweb market where the mechanism to hold money in escrow until the buyer received the goods was expensive and annoying for sellers, so trusted sellers ask buyers to not use it; eventually those sellers take one last batch of orders, don't send anything, and disappear with the money.
You are welcome to use many different payment rails with Amazon, Burger King, etc. Between them Patrick McKenzie and Dan Davies are pretty good on why people use the rails they do, and which blood wrote the financial regulations governing them.
Can't you just whip out a card, stick it in a reader, enter your pin, click "yes" and pay by bank debit? If you are using a smartphone app that is an intermediary right there.
Its hard to be specific without knowing what country you live in.
I live in Germany. I want to pay by bank debit, worldwide, with my smartwatch.
I don’t want the smartwatch maker to be an intermediary to the transaction, it’s just a tool I use to store my payment credentials.
None of this is a problem with a debit card that’s debited to a bank account on real time.