That's going to depend on the store and the shift.

I'm sure you understand that I gave an example that's easy to understand and I'm not trying to discuss the intricate details of being a high performing cashier.

If it's really needed I can come up with a different example, but otherwise just assume it's not a neighborhood pet store, but a very busy and successful supermarket with 35 check out registers that are always busy.

But you can just as easily swap it with an overqualified dentist assistant that provides a massive value by detecting things the dentist misses.

Or a engineer at a mine that's so damn good, that he repeatedly detects machinery failure 5 minutes before it breaks catastrophically (and some of these machines cost millions).

Or a bricklayer that lays three times faster than any other bricklayer. It doesn't matter.

The point is they are supportive roles that can't function independently of the corporation, yet will never receive a salary that's proportional to the value they provide.