For me, it's usually because if I'm ordering something it's for a group of people (family or group of friends), so it's easier to put the order together online

For me, it's usually because if I'm ordering something it's for a group of people (family or group of friends), so it's easier to put the order together online (you can go round the room and ask them what they want, then get them to double check the order at the end). There's also the fact that at a couple of the local places, the staff don't speak English as a first language, which combined with the noise of the shop often leads to you repeating yourself or there being occasional mixups.