Considering that charging is the most dangerous thing a cable can do, Apple's motives for this sort of restrictions can be boiled down to the usual monopolistic approach.
Specifically, note "Mactans"
https://www.forbes.com/sites/andygreenberg/2013/07/31/resear...
"As a proof of concept, the three researchers created a malicious version of an iOS Facebook app that also includes a Trojan that runs in the background, capable of taking screenshots, simulating button touches, and sending data to a remote server."
You must not have been around for the era when data exfiltration via charging cables and bricks was a thing.
Buy a charging cable from some random Chinese reseller on Amazon, and bingo — data in your phones goes back to the PRC.
I still have about five little black USB security dongles in my drawer from this era. They only allowed the charging pins to connect to the phone or computer. The data lines are physically disconnected. We used to call them "charging condoms."
I like Android's AOAP better for this reason.