I still do this! Old books are socially and culturally fascinating; they give you a glimpse into how much society has changed, and also what’s remained the same. The writing styles can be delightfully archaic, but also sometimes amazingly fresh. Nonfiction writers from 1780 can be colloquial and funny as hell.
And man, they wrote about everything. Back in those centuries they wrote books about falling in love via telegraph wires, and about long-distance balloon travel. They wrote books that soberly praised eugenics, and ones that inveighed against it. They published exuberant magazines of men’s fashion and books on how to adopt vegetarian diets. The past being the past, there’s a ton of flat-out nativism, racism, and gibbering misogyny — but also people fighting against that, too.
It’s rarely dull.
Still, sifting through old books can be a hassle. You have to go to those search sites and filter for the right vintage (and public domain status). It’s a pain.