Umm, from their breathing?
Remember that these went up in the first year, before vaccines, before readily available masks, before treatment programs with some history to them. Stores were having trouble keeping minimum wage, uninsured โessential workers,โ and this is one of the concessions they made. I do also remember lots of workers wearing nitrile gloves, before the risk of transmission by contract (touching) was found to be minimal.
Itโs only been 2 1/2 years, and weโre already forgetting what 2020 was like.