But, I need to take quick and dirty photos of batches of cartons showing the integrity of the barcodes on shipping labels. My phone is perfect for this use. I don't think I'd be able to do this with 12MP. Yes, I realize most people don't need this ability, but once you've lived with 21MP it's hard to go down to 12MP.
Oh, I get you. And in that use case, I'll give you that resolution is king. But I've seen plenty of shots from that very same phone where it starts to fall on its face once the light levels start to drop. Once that starts to happen, those tiny pixels that allow you to get that finely detailed image in bright light start to cause problems... small optics need more light... either longer exposure times, higher ISO settings or a (usually) a combination of the two. And that, combined with those same small pixels means noise, lots of noise. And noise can turn what would have been a good picture into a dumpster fire.
This feb, I went to Disney... my wife had her G4 and I my 6P. Her G4 shared the same 1.12 micron pixels that you have in your DT... probably even the same exact pixel tech based on the two sensor's ages. And the G4's aperture was even wider than your DT at f/1.8.
In bright light, mostly interchangeable really, both did the job. But inside attractions, at dusk or at night? It was no contest. Here are two example shots that were close to the same time, the 6P's was actually a bit later. These are both lightly cropped. Sure, the G4 is brighter, but that's about all you can say about it since it sacrificed everything to get it that way. Its overexposed, processed within an inch of its life. You mean, Minnie's dress is red??? Little details... like the staining on the scuppers, shadows behind the characters, gone.
Which one do you think made it into our Disney 2016 album?
6P
G4
Now this was pretty much repeated over and over... any time that light was at a premium, the phone with the larger optics, regardless of how many pixels were stuffed in there, did the better job.
These OEMs aren't picking a sensor for a single application.. they are picking a series of parameters to try to find the best option that fits in the little space they are given. And the options that Google has taken mean that when light levels start to drop, their cameras will be much better than yours than yours will be better than theirs when its the opposite (which, unless you start cropping like crazy, isn't applicable since the 6P takes as good if not better pictures in good lighting pictures too).
You'll search far and wide for a photographer who will gladly give up optical performance for the sake of resolution.