I'll probably shell out for the 16 Pro soon, while upgrading from my beloved (but now aging) 11 Pro. As a somewhat retired landscape professional photographer, it has always been my youth dream to have the smallest gear (for mobility) with acceptable image quality (optimization). Every year, this is coming closer to be a reality.
Results from the main lens of iPhone 15 PM are not much inferior from dSLR quality if shot as ProRaw and in-camera converted to jpeg. Here is a good example:
https://www.dpreview.com/files/p/articles/8615681274/resolution-pro-48mp.jpeg It's precisely detailed with good dynamic range and I don't see any noise or other artefacts like haloes around edges, corner softness, etc. It could even accept a little more sharpness. With a dSLR, one might need a tripod and graduated ND filter for similar result.
Yet, other 2 lens units (UWA and Telephoto) do not seem to be at the same league due to physical constraints (24mm eqv. must be the optimum like 50mm of SLR, enabling smallest size with largest aperture with technical ease), but this main-sub discrimination will likely come to an end in a couple of years.
It is rumoured 16 Pro will get 48 mpx ultrawide. We'll see if it benefits despite of poorer corners. At least, the central area will become more detailed and allows a nice crop to 15 mm eqv. And for the yet 12 mpx 5x camera, I'll try to improve by either opting in 3/2 aspect swipe panorama or stitch multiple vertical frames with an app. By this way, one can almost double the resolution and still have around 3.5-4x (85-90mm eqv.) focal.
iPhone 18 Pro will probably the first pocketable-size phone boasting all 48 mpx raw option bundled with appropriate optics, as a key to IQ. It may happen next year on 17 Pro but it's unlikely knowing Apple's strategies trickling innovation in time, all-48 mpx feature will likely be introduced first on the bulky 17 Pro Max.