I was rocking an iPhone 6. Yes, a 6. My wife had an xs max - two weeks ago she dropped it and it smashed. We went and bought a pair of iPhone 15 pro max phones, fully loaded.

1. they are ridiculously expensive - over 2k a piece. Most people can’t afford that. What happened to sub $1000 phones?
2. yes there’s a lot of improvements over the 6. But the 6 still functioned perfectly - albeit a bit slowly
3. the only improvement I can tell as a user over the xs max is the cameras. They are arguably better. Otherwise it’s the same phone.
4. the software is nearly identical on all three versions. There’s not many “ooo this one does xyz like this, and that’s an improvement”

Bottom line: there just isn’t a reason to upgrade a phone anymore, unless they break. Sales HAS to go down if the price point stays the same or goes up.