I actually think queuing makes more sense. There’s nothing worse than standing at the bar while the bar staff serve regulars/their mates first and studiously ignore you. I have experienced this many times.
When I was young, nearly all customers adhered to basic pub etiquette – if someone came to the bar after me but were served first, they would point out to the barman that I was there before they were. Sadly, even basic manners such as these appear to be dying out in my experience.