Thinking through doubts about reliable hadiths and human mistakes

Salaam, folks. I was talking with someone recently who brought up that even hadiths graded as Sahih might have mistakes because they were passed down by humans-who aren’t perfect. They also said we can use our own ‘aql (reasoning) to dismiss reports if they don’t seem right to us. I’m trying to keep my approach consistent here. Some brothers and sisters respond by pointing out the Qur’an is different because Allah promises to preserve it. But on its own, that feels a bit circular-it assumes the Qur’an is divine to begin with to prove its preservation. That said, even without leaning on that ayah, you can look at history: the Qur’an was memorized by thousands (tawatur), there are early manuscripts, it was standardized early on, and there aren’t rival versions floating around. Here’s where I get stuck, though: The Qur’an was also transmitted through people-memorized, written down, compiled. If ‘humans are fallible’ is enough to make us question Sahih hadith, why doesn’t that same idea shake our trust in the Qur’an’s transmission? So what’s the real, consistent difference in how we know what’s reliable? Is it: 1. A divine promise vs. no promise? 2. The scale of transmission (mass vs. individual chains)? 3. Something totally different? And where do we draw the line-when does personal reasoning trump the methods scholars use to authenticate reports? Just looking for thoughtful reflections, insha’Allah. (For what it’s worth, I personally believe we can’t just doubt solid hadiths only because humans are involved, especially when there’s strong proof they’ve been preserved reliably.)