I worked at a national telecommunications company in sales & service in a store. It was a manufacturer agnostic telco where the overwhelming majority of phones

I worked at a national telecommunications company in sales & service in a store. It was a manufacturer agnostic telco where the overwhelming majority of phones in store weren't Apple, as naturally the store also had Sony, Samsung, LG, Nokia, Huawei etc. At the time Apple only really had two flagship phones. Of course you can't take what I say as gospel for many of the reasons you mentioned, but it's my experience.