As a self-taught developer I absolutely promise you don't need to go to any school to learn the requisite skills to achieve a variety of complex things. You absolutely can learn from both trial and observation.
Yes, everyone actually is potentially a developer, because there are no baselines to the contrary. I have met many developers that should never have been there professionally. Not everybody is capable of actual engineering though, as engineers follow processes and measure things. So many people writing code for a living absolutely cannot measure things.
I think your fundamental problem is loss of empathy. Perhaps you understand your own limitations but do not seem to understand other people learn differently than you do or may have wildly different experiences than you have.