I'm torn when I read articles like this. On the one hand, I've spent many happy hours browsing round second-hand bookshops (a particular favourite memory was discovering the unabridged Gulag Archipelago while on a trip to NYC). On the other, the democratising effect of publishing leads to things like this - https://www.theguardian.com/focus/2020/aug/16/literary-world... - which, while potentially problematic on the surface, means that a much larger number of people can be published, no matter what their social status or connections. I've recently been reading Bruno Schulz - https://en.wikipedia.org/wiki/Bruno_Schulz - and if it wasn't for the intercession of someone powerful in the Polish literary world we would never have read his work (and, thanks to the Nazis, unfortunately we had even less than we might have had). What gems by marginalised authors might we not have read without this "excess" of publishing? Personally, I think this abundance of new published writing (including really interesting examples of self-publishing like Your Name Here by Helen Dewitt) is part of what makes second-hand bookshops less attractive. There is simply so much great stuff being written now by people who would never previously have had an audience, as well as unjustly-neglected authors being rediscovered. I used to feel like I knew most fiction authors' names in second-hand bookshops, even if only by reputation, but I'm not sure that would be the case any more. On balance I think I'd rather have a broader set of voices than a limited selection of second-hand books. And when you also have access to older titles that you might be interested in on abebooks, you can follow your own literary path rather than be guided by someone else's opinions about what's "important".

Edit: Thinking about this more, maybe it's because I'm in my late 40s now, but I get a lot of good recommendations from friends who have been reading all their lives, so I don't feel the need for anyone else to recommend things. My "to read" pile is huge as it is! I guess one thing second-hand shops were good for was suggesting things to me that I might not have read otherwise. But personally I think the internet, particularly Wikipedia and niche blogs, gives me a really good route to the next thing I want to read. After reading Bruno Schulz I've started delving into Polish fiction, and it feels like I've struck yet another goldmine.