You can argue that there ought to be a Mexican restaurant in your town. You can tell people how badly the town needs Mexican food, how well such a restaurant would do, and how much better off everyone would be. You can describe the benefits people will get from consuming more Mexican, the wonders of greater choice, how it’s a good deal for the money, why Mexican makes you happy, and why the current dining establishments are insufficiently serving the population.
Or you can open a Mexican restaurant.
You and your customers will find out quickly whether and to what extent your claims are true. If so, you’ll benefit and so will they. If not, well…
Most of our beliefs aren’t worth risking much to prove, but maybe some are, and maybe more of them than you think. The easier it becomes to start a business and the lower the costs due to technological advances, the more of our beliefs about what ought to be can be tested. If you want something, create it! If you see something you don’t like, compete with it!