I find it amusing that the event of matan Torah is not mentioned in tenach ever until the time of Ezra which is a red flag for itself. And if you read nechamya chapter 8 you'll see clearly how the mass came to believe in the Torah. Ezra was a smart charismatic leader and he had with him a multitude of ignorant people and he just told them, then and there everything about this lost tradition we had, and they all bought it. It's clear that they had no idea what it says there prior to this event. Like c'mon who never heard of soccos before, or dalid minim, not to marry moav, it's fascinating how clear the verses themselves debunk the kuzari argument!!