Learning through trial and error is so damn useful because that's how our brain is designed to learn.
Whenever we make a prediction, dopamine neurons in our brain start to fire, triggering a feeling of expectation. If we predict right, we get a surge of dopamine and some positive reinforcement. If we get it wrong, the dopamine neurons stop firing which, aside from making us feel like crap, serves as a signal that the prediction needs to be revised. Normal learning operates by consciously acquiring information and hoping it eventually filters down into the subconscious. Trial and error, on the other hand, puts a direct line into our subconscious - it's much more efficient.
Whenever we make a prediction, dopamine neurons in our brain start to fire, triggering a feeling of expectation. If we predict right, we get a surge of dopamine and some positive reinforcement. If we get it wrong, the dopamine neurons stop firing which, aside from making us feel like crap, serves as a signal that the prediction needs to be revised. Normal learning operates by consciously acquiring information and hoping it eventually filters down into the subconscious. Trial and error, on the other hand, puts a direct line into our subconscious - it's much more efficient.