I get the joke but you don't send Amazon money, you just tell someone else (after multiple third-parties and fees) to let them take some of the money you store

I get the joke but you don't send Amazon money, you just tell someone else (after multiple third-parties and fees) to let them take some of the money you store with them. It's not at all like handing someone some cash, I never "signed up" to my local grocery store and I don't need to login to make a purchase, I can just hand them some cash.