Are you arguing that there is some (other) system that solves the issue of over-selling and under-delivering? More constructively, I don't think anyone argues

Are you arguing that there is some (other) system that solves the issue of over-selling and under-delivering? More constructively, I don't think anyone argues that there isn't (rudely speaking) a broad supply of fools waiting to be parted from their money. For the purpose of this forum the question is what can the clients (quite possible technically weak which is why they need to hire out) do to improve their odds.