Those big holes to put your hands through might have something to do with the comments.Spacing for lines still makes sense. Covid is spread is airborne. The closer you are, the more concentrated it is.
If I were a cashier I‘d appreciate maintaining the plastic guards. It blocks the direct flow of air. I don’t understand the comments thinking they should be removed.
Of course, the virus is courteous & would never enter those holes. That's also why it would never infect someone while they're dining.