Er, no. You bought a bunch of silicon off the shelf, and you had to integrate it. Several orders of magnitude less work.
Fifteen developers, and two years? Not mentioned, but this means you didn't write the telephony stack either.
iMX8M bringup, driver development, software integration. This is real work, but it's a tiny fraction of what goes into making your own phone.
Hoping you sell enough of these that you manage to attract adversarial attention. Because how you deal with that will be the true test of your commitment...