The headline spoils the ending, but I thought it would be fun to compare Apple's best of 2016 vs their current leading iPhone camera (technically second best, but it's close enough).
First up is a photo in the dead of night. The iPhone 12 Pro clearly wipes the floor with the iPhone 7 here, and it should, as Night Mode is the biggest new camera feature to come to iPhones since 2016 (you could maybe argue ultrawide too).
The iPhone 12 Pro shot has more detail everywhere, does not blow out the lights nearly as much, and simply has more dynamic range to show light and dark details simultaneously.
Zooming in shows this more clearly, revealing sharp lines on the siding, less blow out on the lights, and infinitely less noise in the sky.
Good Light, Doggo
This is more of a fair match for the iPhone 7, and it does indeed do much better in this case. In fact, depending on your preferences, you may prefer its colors to the iPhone 12 Pro's! I'd say the 7 is a little more accurate to life, while the 12 Pro is a little cool, making dark gray things in the shot (hoodie and car door) to look a little blue.
When we get closer the differences become more clear.
The iPhone 12 Pro captures much more of each individual hair, the nose maintains more texture and information in general, and the background is actually blurred and not just muddy.
This one was downright shocking to me. Across the board, the iPhone 12 Pro blows the 7 out of the water. There is actual information in the darker areas and the color of the grass comes through much better.
Zooming in only confirms these feelings, as the wooden fence and playground in the background are simply "concepts" in the iPhone 7 shot, but have actual texture and clarity in the 12 Pro version. The tree branches as well are clearly defined and look sharp instead of blurry.
This last bit is likely due to the less advanced photo merging that was not mastered for another year or two.
Selfies, Good Light
Finally, there's the selfie camera, which I suspected would show the least difference, and that ended up being the case. At first glance they look very similar, with the iPhone 12 Pro again looking cooler than the iPhone 7.
Zooming in we do see some marked improvements, though. The pores in my face are all too clearly visible and my eyes are more vibrant.
I did this comparison mostly for fun, but also because we often see camera shootouts between this year's phone vs last year's model, which is only so relevant to how people actually shop for phones. Someone with an iPhone 7 very well may have upgraded to the XS or 11, but there are millions of them who just upgraded to the iPhone 12 line this year. Hell, there are millions more who will wait until next year or even later!
As tech reviewers, we spend a lot of time splitting hairs on nearly identical cameras and it sometimes feels like we're not making tons of progress. When we look at a more realistic upgrade path for consumers, we see massive progress that people will notice and get more excited for than any of us who upgrade every year will ever experience.
Note: This comparison is just the tip of the iceberg too. I didn't do video, zoom shots, ultrawide anything, or portrait mode, but hopefully these few examples give an idea of the magnitude of progress made in a few short years.