I agree with you here that to start out you need to do everything yourself. Once you have built a better mouse trap and have a revenue flow, it is the time to figure out how to spend the money. So that you are getting the right ROI.
There's only some much time. At some point you will need to spend money. If not on ads, money can be spent on promotion and content.
But you are right that most people waste their money. They do not spend it wisely or don't even know how to manage ppc, etc.