Does it really take hours at the register?

I’ve binged a few episodes of extreme couponers. What strikes me is they all say something like at the grocery store for 8 hours, at the register for 2+

I’m sorry but really? Is this all fake or does it really take HOURS at the register? Don’t you feel like an asshole holding everyone up and just being obnoxious to the cashier? I could never do that. The look of just hatred and dread on the cashiers face would make me want to go away. I can’t imagine taking up several hours of someone’s time for something that’s supposed to take like 2 mins tops to cash out