I worked as a cashier years ago and while I will say, it’s probably better for your health to be standing (I work a desk job now and have definitely put on some lbs since leaving that line of work). It’s still absolutely ridiculous that employers won’t allow cashiers to have a chair. It’s just so they can pull that if you’ve got time to lean you’ve got time to clean bullshit on you. Instead of resting your body during lulls, they want you cleaning your register, stocking shelves, facing product or “fishing” for customers who need to checkout and are too dumb to get in the check stand with no line and head straight for the 4 person long line because of herd mentality. It’s really rough on the feet and back to stand in one place all day without being allowed to sit.
I don’t think standing all day like that is necessarily better, as it can cause other health complications. I did a light google search (i know, not the most extensive research) and the results suggest that standing for long periods can cause joint pain and put folks at a higher risk of problems with vericose veins. I understand that cashiers may do other things around the store, but some stand at the register for hours on end and that’s not much better than sitting.
https://www.webmd.com/fitness-exercise/standing-desks-help-beat-inactivity