Indeed. Anecdotally I’ve seen in a few places where the going rate for one carrier or another is actually a bit higher than unlocked because people aren’t that well-informed and think “I need a Verizon phone cuz I’m on Verizon.”

Which was pretty universally true in the USA 15 years ago.

Before Verizon stopped using pre-LTE, most unlocked phones wouldn't work on Verizon. I imagine you get burned by that once, and then you pay attention longer than necessary.