Fun fact: if you think cashiers and other tellers shouldn't be allowed to sit, you're an asshat.
Go stand 8 hours in a phone booth as old fashioned as your dumb ideas of people being forced into uncomfortability and pain because "oh no! Sitting means lazy!" to you.
30 years ago I worked as a cashier in a grocery store. That job still would have sucked even if we had been allowed to sit down. I will never work retail again and I always try to show kindness to clerks and restaurant workers.
When Free and I had our bakery I worked the front counter and had several people scoff at me for sitting in a chair as I worked.
Several folks said "I'm surprised you boss lets you sit" and it was fun to tell them "Well I'm the boss and its stupid to make people stand for no reason"
The law over here requires seating as a means of labour protection. It's virtually a health risk that physically harms employees for no particular reason other than to save a few bucks on cheap chairs or maybe outright cruelty.