Some smartphones are locked down by their vendors. There's plenty of options to get full root access on something that's for all intents and purposes a smartphone, especially if you don't particularly care about warranty and/or keeping commerical apps functional.
The radio on all commercially available smartphones are locked down to meet regulatory requirements and runs on an entirely different CPU from the Android OS that you might have root on.
True but they are commonly used to control other non-consumer (e.g. unregulated) radios via GPIO, and in POCs for threat exploitation demonstrations which are all over YouTube for idiots to mimic... and unlike phones they aren't carried around by almost everyone on a daily basis.
