The original topic here was "why don't planes have GPS trackers on them and constantly report in, if trackers are so cheap and every car/truck/container/phone on the planet can have one?"
How does a plane get data back to the ground when it's 7 miles up and 1000 miles from shore? You have to have a satellite or long-range VHF link.
Those shipping container trackers use GSM to call home. They're cell phones. What happens when that container is in the middle of the Pacific Ocean?