Right, which means you have to make time for it. Sure, you can make up stuff to do while you wait, but it's still a long enough amount of time that you have to

Right, which means you have to make time for it. Sure, you can make up stuff to do while you wait, but it's still a long enough amount of time that you have to work it into your schedule. Filling a tank is quick enough that you don't have to do that. You can just fill your tank on an as-needed basis without planning for it.