As a frequent online shopper I have a few issues with all deliverers.
Couriers that promise delivery today, show it's out for delivery,then don't arrive. Those that obviously played their lunch break footie match with my parcel. Those that seems to take forever to deliver. And finally there's Royal Mail. They too can have problems, several items disappear each year, without trace. Several arrive in poor condition and sometimes they drop a card saying I wasn't in, when I was. Then there's the joy of collecting the parcel. My local office, 5 miles away, is open for my inconvenience between 7am and noon, except for Saturday when it closes at 10am.
All the delivery firms operating in the UK have been to my door this year, 95% of my stuff arrives without any issues, but of the other 5% most problematic, by %age of actual deliveries by each firm is Yodel, followed closely, I'm afraid, by Royal Mail.
I better be careful what I say about them, they might find out where I live!