The Enlightenment (the Age of Reason) was animated by the realization that traditional sources of belief are actually generators of error. Things like authority, tradition, dogma, charisma, hermeneutic parsing of sacred texts, the subjective glow of certainty.

Rationality matters to our lives. A People who follow normative models, avoid cognitive fallacies (on average). They have fewer accidents and mishaps. They have better financial, health, and employment outcomes. And they are 3 times less likely to be swindled by medical or psychic charlatans.

Rationality drives progress. Historically, we humans have made great progress against famine, extreme poverty, child mortality, and war. Longevity, peace, prosperity, safety, quality of life have all increased over time when they are measured quantitatively. Progress comes from deploying rationality to improve human flourishing. If we continue to apply rationality to make our lives better progress can continue. If we don't, it may not.

Rationality Promoting Institutions:
1 Science with its demand for empirical testing and peer review
2 Democratic government with its checks and balances
3 Journalism with its commitment to editing and factchecking
4 The judicial system with adversarial proceedings
5 Academia with freedom of inquiry and open debate
6 Wikipedia: editing with commitment to neutrality & objectivity

Reason is non-negotiable. Try to argue against it, or to exclude it from some realm of knowledge, and you've already lost the argument, because you're using reason to make your case.