I've been saying this for a couple years now. The problem is the financing deals that make it too easy for people to spend money they don't have with a company that could easily survive on lower margins.
All of these phones have gotten so expensive, while also being mainstreamed into society, such that everybody feels the need to finance a phone they can't afford in the way middle class folks only ever needed to finance a car or a house. Now the smartphone is, yet another, "thing" that the average person will need to finance in order to purchase.
Few people "need" the Pro models, but because they are artificially made affordable they sell well. And given how people treat their phones and how fast the technology evolves, it's not even something like a car that you can repair to keep running for a decade or longer. We just saw non-VoLTE phones, which were available to buy until around 2015, getting shut off when carriers shut down UMTS and CDMA over the past year. Most people might not want to use a 7-year-old phone; but even if you can replace the battery and repair parts that break, software updates (including security fixes) end by then and the cellular tech is sunset rendering the phone useless out in the world, so it's not even an option when the technology changes that rapidly.
The solution is for people to stop buying as frequently and to stop buying the big expensive models, even when 2-3 year 0% interest financing is offered. Apple needs to see actual sales declines to start reacting -- it's the only way they'll make a change to their pricing strategy.