It's not just about (B). There is a tricky balancing act involved. A company that does too much (B) ends up with an app that users don't like and stop using. A company that does too much (A) produces a beloved app right up until the point that the company runs out of money and folds.
Because they have to compete with people doing lots of (B), and giving the app away for free. I'm increasingly feeling that "free + ads/surveillance" is the problem.