Oral Torah

Greetings to Rabbi Michael Avraham,
I understand that you believe that the Toshab'a developed relatively late, only during the Second Temple period. Also, it is implied from your words that until the Second Temple period, the halakhic tradition was oriented toward the simplification of the words of the Bible, and not rabbis that are far from the simplification of the Bible.
If that's the case, I wanted to ask how it was possible for the Sages to innovate by taking the literal interpretations of the Bible out of their literal interpretations in practical matters of halakhic law? After all, they did not have an ancient tradition that this was the right and proper thing to do. And if this is an explanation, it is not at all clear that this is indeed the proper thing to do. So is it not appropriate in our day to return to the literal interpretation of the Bible?