Agreed. I mean, this applies to various kinds of things, not just libraries: there used to be many more retail stores of various kinds (record stores, video rental shops, hobby stores, whatever) where you could browse and encounter things you hadn't intended or expected to encounter.
I was thinking of record stores as well. I spent so much of my life in those. Now on the rare occasion when I go into one, I have the uncanny sense of being back in the distant past, or back in a dream I had mostly woken up from.
I've found myself going to thrift stores a lot more these days than I used to because they're among the dwindling number of places left where there's still that experience of browsing and frequently seeing stuff you didn't expect to see.
