Yes, the little things add up if you really care about them, but the “normal” people who just use their phone for basic tasks and don’t really think about it are hardly going to notice any changes. Although camera processing does improve each year still, as you say, and I have already got some amazing shots on my iPhone 15 Pro Max - but, even then, you arguably have to care about photography at least to some degree otherwise you won’t appreciate the improvements. Most people these days just take photos and videos to post on Instagram, Snapchat & TikTok, which upload compressed anyway.

Of course, most “average Joe” iPhone users don’t have a Pro model, so it’s immediately noticeable.

Even an iPhone 13 Pro is going to look better than an iPhone 15 in this regard.