> All those geniuses hired and over years and years no one came up with another business model but ads

This isn't true, there were many other ideas. It's just that only KPI was how much money they can make, thus ads won. Companies don't have an axis of ethics or morality.

Ideas don't count - it's persuasion and execution that matter. One of the several reasons that the rule is not ruled by smartness/rationality.