My local grocery store doesn't provide receipts unless you ask
At least if you pay via Apple Pay (and presumably other contactless systems)
When I pay via debit card (I got one recently for a rebate and had to use it) they still gave me a receipt without asking - I wonder if that's some sort of payment processor rule they have no choice about? But when I pay via Apple Pay at first they'd ask if I wanted a receipt, now they don't even ask and will only provide receipts if you ask.
I can see the amounts things are being rung up for on the screen at the register, and while I don't always pay attention if there is some sort of deal I want to make sure I get I usually watch for that. What's the point of getting a receipt whether paper or electronic to tell me what I bought and what it cost? Its not like I can go back to the grocery store and return a gallon of milk or a couple pounds of apples.
So this seems like the best solution of all. If I'm buying something I think I might need to return having some sort of receipt is necessary. But I'm torn whether paper or electronic is better. If it is electronic and in my phone then I don't have to worry about losing it. But if I can't get cellular service in the store (can be a problem in those big box stores with metal roofs) then I wouldn't be able to access it and would want paper...