The slides he took were for his own amusement, and the family’s, just like most other people’s photos. They weren’t shared instantly with the world. That was very much a professional’s conceit.
Now, everyone with a phone has a camera that’s very high resolution and usually internet-connected. The cameras keep getting better (for no good reason that I can tell) while the phone itself remains relatively unchanged. Sure, it can run more apps, so it’s now pretty much a personal computer that incidentally includes a phone,, but because we feel the need to be always connected, we’ve always got a camera.
Consequently, everyone feels the need to overshare every moment of their life, as if they will somehow become important, or that we’ll magically care. It’s too cheap and it’s too easy to spam the world with the beautiful moments that, incidentally, are just like everyone else’s beautiful moments.
My grandfather had a probably almost-unique collection of all 250-plus courthouses of Texas at the time, without competing with anyone to get them, just because he thought it was a neat idea. Now, there are probably hundreds of that collection, produced by ridulously competitive amateurs who want to be Instagram-famous.