Now the question is: should the icons represent something "iconic" or something that most people use?
I don't know what you mean by "iconic". If you mean "abstract and without independently-identifiable meaning", then I think in general, no. Icons should be immediately identifiable when possible. The overlapping rainbow paint chips that make up the current photos icon seems utterly meaningless. The camera was meaningful. A stack of photos would be meaningful. An abstracted "photo" like Windows 10 uses (and like Google uses in the sidebar of their online photos app) would be meaningful.
For the record, I think Android/Google's photos icon is also utterly meaningless to most people. I think it's supposed to represent a camera aperture (same as Apple's icon?), but most people probably don't know what a mechanical aperture is.
For example, in the current world maybe 10% of the people are taking pictures with actual cameras but we still represent the camera as a "box with a huge lens". Few people use land lines but the phone icon is still a banana. To send and e-mail in general we use an envelope but we send way more electronic messages than snail mail.
So you either use something "iconic", or every icon is just a small screenshot, or I guess you make something up that is meaningless.
Who are these supposed people who are buying Macs but have never seen a camera? This set of people must be miniscule if not empty.
Cameras are still in use, even if most people have replaced them with smartphones. Walk around any city and you'll see gobs of people taking selfies on their phones, but you'll also see a decent number of people carrying dedicated cameras.