I agree. I've started thinking about phones like cars. I'd never consider buying a brand new car, and I generally wouldn't buy a brand new phone either (although they're not quite as expensive as cars). I've found that year-old models are typically around half the price of new ones.
1 year old sure unlikely 50% cheap but 2 years old for sure can get for 50%. I don't see much difference between iphone 15 pro and iphone 17 pro. Honestly I'm still having iphone 13 mini and don't see much reason to upgrade but if decide to upgrade I will most likely buy 2nd hand iphone 15 pro.