Back in the day, I shopped at the one grocery store in a bit of a food desert. They'd have all...I don't remember 10? 12?...checkout lines open all day, and you're still guaranteed to spend half an hour in line. If they could have replaced 2 checkout lines with 6 self-check kiosks, or 4 & 12, it would have helped a lot, but they hadn't been invented yet.

Now, I shop in a better neighborhood where they have 6 kiosks, one staffed checkout, and 8 lanes closed. Start with a technical solution to a real problem, and some MBA is going to come in and figure out how to turn it back into a problem.

"If" in one hand, shit in the other. Which fills up first?

following the airline model

? Are you talking about, like, baggage prices?

Iirc, airline margins are super thin, and their customers are extremely price sensitive. In order to stay competitive, airlines need to be able to sell their customers on the lowest possible flight price, while still not losing money on every single flight. The solution is to charge the customer more directly for the scarce resources they use on a flight. Extra weight on the plane means more fuel used to reach the destination. Charging for each checked bag rewards people for travelling light, while giving everyone a free bag punishes the light traveller with higher fares. Sure, the byzantine fee structure in the booking process is annoying - but at the end of the day, flights are now extremely cheap historically speaking, and a pay-for-what-you-use model makes sense.

Of course, the actual solution is to have a better system of busses and trains. And the airline industry is always lobbying against that. But I'm not sure what the comparable action in the grocery industry would be.

Until you get stuck between Ethel (who is trying to fill out a paper check and make small talk because she's lonely) and Bob (who has no sense of personal space and smells like he doesn't know how to wipe).

Non-self-checkout sucks.