Why you use theories which are based on unrealistic assumptions?

Theories based on unrealistic assumptions can provide simplified frameworks that help us understand complex phenomena by isolating key variables and relationships. They serve as foundational models that can be systematically tested and refined. Moreover, these assumptions often allow for clearer predictions and insights, which can be useful in guiding empirical research and practical applications, even if they don't perfectly mirror reality. Ultimately, they can stimulate critical thinking and discussion about underlying processes and potential real-world implications.