I agree. It might be summed up as "Why other people have different preferences than I do ?"
"Why do people buy expensive clothes/cars/watches/tech ?"
Mostly because other people are different from you and will place different value to things than what you might.
Their financial condition might also differ from yours, and maybe $800 dollars are pocket money for them.
It is surprsing in how many contexts the same concept can be applied: "Why so many people complain about bezels ?"
Because other people are different from you, and possibly will place more value on a phone's aesthetics rather than its software or processing power.
TL;DR A lot of other people are different from you. It is surprising to me how this does not seem to be common knowledge.
Apple is known for supporting their hardware for a looong time. You can for example, upgrade a 5S (2013) to iOS11. That 8/X people are buying can be expected to be fully usable through 2023, whereas for Android that's ~2 years.
You can still download older versions of apps from the App Store for iOS back to 4. I recently reset an old first gen iPad and was able to use older versions of Netflix, Hulu, Crackle, Spotify, Plex and the entire iWork suits.
There must be a term for this kind of question. To answer it, yes. Look at Apple’s average selling price and people are buying maxed out iPhone 8s and X’s.
But that question is like the old internet trope - “I haven’t had a television in 10 years. Do people still watch TV?”