1) battery dying / not lasting enough
2) shattered glasses whose replacement costs 35-40% of the cost of the phone new (for budget/mid-range phones, not everybody has iPhones)
distant 3rd) not enough free internal storage
Are non-premium new cars a scam too?
sure on highest end phones you have very good cameras since a long time by now, but even there they find improvements here and there (e.g. zoom, low light pictures, even better image stabilization)
but middle to lower end phones are still have major improvements in every generation of a certain brand/line/price category. And you might be satisfied with a "acceptable" quality camera, until everyone around you has way nicer photos, or you now have a reason to make photes you didn't had in the past, or you get older and your hands a bit unsteady etc.
This is also reflected in the increasing support durations from major manufacturers.
Secondly, what you said may have been true in the past, when smartphones were rapidly evolving and upgrade cycles were short, but people are holding on to their devices for longer now, so its possible its becoming a problem again.
Not sure how comparable that is when considering that the devices are also commonly required as ticket on public transport with no offline fallback (going so far as to include animations on the screen so you can't send a screenshot to a friend or print it out -- no, I have no idea why they think you can't send a video to a friend). Having 10 minutes of use time is simply not on the table, and GP was probably not talking about that class of phones (pre-"smart" phone) in the first place
https://www.bestbuy.com/site/external-battery-packs/usb-c-po...
Now that this doesn't happen, the driver of obsolescence is the battery, which is much less defensible because you can swap it much more easily than "the whole internals of the phone".