I'm guessing here but most likely because of connectivity and telemetry.
Say the printer connects via Bluetooth. If the Bluetooth is damaged on the device then you wouldn't be able to print so a myDevice without WiFi is a lemon anyways. The way they have it now is every printer has its own IP address and connects to the internet and listens for stuff from HQ. By doing this they can easily monitor how often we go through our printers and what type of things we print and when we print them.
If you noticed the barcode is super easy to decypher and even mess around with. All it is is the store number, "PRT", Then the printer number. So T1234PRT0001 as a barcode I could scan and it knows the store you are printing to and it knows what printer number it is.
While you do all this the printer is listening waiting to see if there is a request for T1234PRT0001 and when it does it downloads it and it prints it!
All of this happens very quickly because it's super small files.
While it does sound over-complicated and it kinda is for what it is but it works!
Now, why do we do all this? I'm glad you asked. Next question.
Side note but I'm new here and no matter what article I go to you are ALWAYS there LOL. I was just reading on the Call Buttons and bam you were a comment.