Validation is shorthand for saying "I don't have deterministic skills or knowledge hence I will rely on user behaviour to drive the product".

Works out for many people and usually ideal for beginners. But post a couple of years, if validation is still your primary model, your model tells you how clueless you are in your domain.

Make logical derivations. Build. Determinism is a luxury only affordable for the ones who put in the effort. Others are doomed to chase validation for eternity.