Google, Yelp, Lyft, and Uber all benefit from network effects. Many businesses do not. E.g. if you're selling books, the fact 200 other people bought the book d

Google, Yelp, Lyft, and Uber all benefit from network effects. Many businesses do not. E.g. if you're selling books, the fact 200 other people bought the book doesn't make the book more useful to purchaser 201. If you don't care about network effects, why is competition a problem?