I don't when alone. I carry enough food for the entire trip and will stow a 3rd bottle in a jersey pocket. You often can't get in "great riding" if you're always confined to being within stopping distance of a rest stop.
This is usually good for up to a 100k distance. Century? I'll loop the route by a park with a known water fountain and I carry my drink mix in a plastic sandwich baggie.
Most times, the only stoppage time on a metric is to wait at a traffic light or intersection. Eat on the move, maybe unwrap it and start eating at the light.
With a group? You've got a group and always someone to watch bikes while another orders a coffee.