I think most 11 Pro/Pro Max buyers are 8 and prior owners. Probably less and less X/XS/XS Max upgraders outside of the have to update every year folks. I was one of those and am keeping my 2017 X for a 3rd year.
I'm an XS MAX owner buying/trading in for the 11 Pro Max.
And to the guy wondering why finance - when I could buy outright - because its nicer to pay just a little bit interest free instead of the whole amount up front. I could buy many 11 Max phones, in cash if I preferred but this helps budget money over time. Plus, when next years phone comes around, I can do the same thing.
I will also pay less per month with the upgrade. I was paying $45 per month (approx) for XS Max Pro 256 GB. And will now pay $35 for the 11 Pro Max 512 GB.
I'm upgrading for double the memory (going from 256 to 512), Wifi 6 and the better battery. Also, as an unexpected perk, I will get the Apple TV+ for a year (would've checked it out anyway.) Oh, and the nice camera upgrades.
I was given $600 credit for the phone (represents about how much I've paid in already). Sure I could've sold it on the market myself as I've done countless other iPhones, iPads and Macs, but me being 50 years old, that little bit of extra time for the hassle and general craigslist/facebook marketplace stress, is more than I have time for.
The one big thing I now appreciate is - take care of yourself in the little time we have on this planet. Have fun, enjoy the little things and learn to play. For me, these little gadgets are all of that and more. My 3 year old son has helped me appreciate all of this and so much more again.