In my childhood, slide shows were very deliberately curated, in no small part because the presentation of the slides was a relatively elaborate, shared family event.

But curation was done mainly by the creators, who were the people who were able to do the creation in the first place (professional photographers, people who could afford to buy the expensive camera, people who could afford the software for editing photos/slideshows in mass etc.). Now everyone can curate, and consumers can actually pick which curated collection is truly the best.

But what does 'best' even mean in this context? A photographer sharing their 'best' photos was some combination of sharing their personal perspective and their effort to capture shared memories on behalf of others. So yeah it was a limited/privileged (often patriarchal) role. What they picked was interpretive, but that curation was part of the expression/information the viewer was experiencing.

We can mix and match the media we choose to view or keep so easily, when previously there was so much more material and opportunity cost to choosing what to shoot, develop, keep, and share. I think that inevitably loses some meaning.

Curation was implicit when the cost of image creation was high and authors had to consider the photos they were taking beforehand. Now curation comes afterward.