In hindsight, the 15 Pro is turning out to be one of the most future-proofed iPhones in quite a while.
Not only did the 16/16 Pro only get a minor cellular upgrade with the Qualcomm X71 this year instead of a bigger upgrade with the X75, but the 15 Pro hardware is adequate enough to offer all the same Apple Intelligence features that the 16 models have gotten so far. Aside from the camera control button and Wi-Fi 7, there is little else different about the 15 Pro versus the 16 Pro from what I can see.