The trouble is that peoples' self-evaluation of things that they believe are helping them is generally poor, and there's, at best, weak and conflicting evidence

The trouble is that peoples' self-evaluation of things that they believe are helping them is generally poor, and there's, at best, weak and conflicting evidence which is _not_ based on polling users. In particular, "producing stuff" is not necessarily "creating value"; some stuff has _negative_ value.