I had had the iPhone Pro 13 for four full years, with a battery level of 88%. I planned to go 1-2 years more before upgrading. Verizon suddenly offered $1000 for a trade-in for the iPhone 16 Pro. With accumulated Verizon "dollars", the transaction, including all fees, cost me $5. I figured a new battery would cost $100, so at worst, I have a new battery for $5.
What I found was that the audio quality was much superior to the 13, battery life had improved significantly, and the system was noticeably faster (not a big deal, since the 13 was plenty fast).
I'm hard of hearing, so the improved audio for calls, music, and TV streaming was just what the audiologist should have ordered.
A fantastic deal for an excellent phone, but would the lower trade-in value of the 13 for a new 17 have made the difference worth paying? Unless I hear that there has been another leap in audio quality, I will be letting well enough alone.