Ok. Yeah you’re right I’m just crazy I’ve never heard a cashier open and say “I’ll take the next person in line please.”

Ok American, please consider that chatty store employees are not actually normal outside your corner of the world.

Next time I’ll make sure to elbow the old lady in front of me and rush over.

This is just absolutely meaningless hyperbole because you don't actually have anything meaningful to counter.
Literally no one says to outright fight over the spots of a newly opened line.
If a new line opens, the only thing that determines the new lines order, is who got their ass moving first.