All cashiers sit in Europe, at least in the countries I've seen. But there were quite some scandals of how Lidl (not Aldi) handles toilet breaks and humiliates women cashiers on their period by having them wear bracelets so the manager knows they are allowed a little more toilet breaks.

>I can't imagine how much less productive I'd be if I could never sit down at work.

This is the rule for FC employees at Amazon - you can squat, or kneel, but never sit.

They say it's a safety issue, but I suspect they really just consider pain to be a more effective motivator than comfort.