Since January 15, 2008 I've taken 18,784 photos with 7 different iPhone models.
- iPhone 1 (1,486 over 1,482 days)
- iPhone 3GS (2,186 over 670 days)
- iPhone 4S (3,344 over 803 days)
- iPhone 5S (3,051 over 751 days)
- iPhone 6S (3,913 1,104 days)
- iPhone 8+ (4,804 over 746 days)
- iPhone 11 Pro Max (3,091 over 664 days [as of 08-07-21] and counting)
Generally I've taken more photos with each successive iPhone model, with a little lull at 5S and 6S. The 11 Pro Max is probably going to come in lower just due to COVID. We haven't travelled hardly at all and that tends to be when I add a good number of photos to the collection.

I'm not sure if I think I've become a better photographer or if the camera technology just generates better photos, but over time the number of favorites has increased. Again, the 11 Pro Max is a COVID outlier.

Not exactly riveting data analysis, but the air quality is crap today so I was stuck inside and this is all I could think up.
Update: Based on some feedback I have corrected the number formating and added the number of days I had each phone.