2) I buy many books for my child. Amazon is pretty hopeless at recommending books to me, even though I've seeded it with knowledge of the books I've bought. So I turn to human curation: the Kate Greenaway medal focuses on excellent illustration in books for children. That list is an excellent source for books. Then one or two degrees of separation (eg, other books the illustrator has worked on, or other books the author of the winning book has written) get you hundreds of excellent books. Someone scraping this list and using affiliate links could probably make a bit of passive income.
Apps are indeed terrible. The algorithms are shit because people buy shit, so they suggest shit. Curated apps stores have been tried (on Android) and there are blogs about apps. The problem is that most money is made from these terrible freemium games that are no better than slot machines. So the curators get paid off, or end up promoting the stuff people want (slot machine-like shit)