Just like with some car manufacturers, if you want e.g. increased safety or radar cruise control, you also need $10k of leather seats and sunroofs; by removing previous Pro models, Apple basically adds a massive price premium to the zoom lens.

As this is honestly the only thing I would need from a new phone, my wife and I stay on our iPhone XR year after year. I just can't pay $1500CAD merely to get more optical zoom than my existing phone :-/