I know in Japan for instance, there’s a unmanned store where you can buy things with the only thing meeting you near the front entrance & exit is self checkout. It’s a trust based system where you walk in select what you want (without locking any essential or mundane item behind plexiglass), as in they depend on individuals having common sense on not stealing paying via a “honesty box” based on a honor system.
Yes. You’re likely to see one at a busy airport.
You get in by presenting a form of payment. You take what you want and walk out. You get charged for it.
The concept works, but only when labor costs are extremely high. Right now, that seems to be only airports.