I've always been fascinated why in the US the "Cleared to Land" from ATC is often given as soon as the Tower is called regardless of if traffic is still departing, or other traffic is landing ahead, or if some plane is crossing, whereas in the UK, it's only given when nothing else is on the runway or due to land or take off ahead of you?
I would assume the UK one is "safer", but perhaps the US way is easier for ATC, and also doesn't stress the crew waiting for a low altitude clearance.
Also which one is the International default? And is there any legitimate reason why you want to have two different ways? Is there something uniquely different about UK and US airports which means both types are needed?