How would we pay for goods with Bitcoin

If big chains (Walmart, Apple, Amazon, Tesla, etc) started excepting bitcoin and crypto in general, would it all be government regulated? Say I have Bitcoin that I want to spend instead of cashing it out, would you just scan your barcode and the government has zero knowledge of who’s making the transaction or would it be more complicated like those companies making centralized exchanges with KYC and you pay using a card that they give you.