How Much Of Sunnah Was Preserved Before Prophet (AS)?
I don’t agree with your premise about the Quran; it is true that we can reach the one true qiraat with a little effort, but when you go to Morocco and nearby regions, you have to use those arguments to convince people about Qiraat aamah (ordinary Muslim still thinks there are seven different Qiraats of Quran as allowed by God himself). You have to refer to history and fiqh to make them realize of the condition and circumstances under which Qiraat of Nafi was implemented in those regions. This whole activity doesn’t bring into question the ijma and quoli tawatur of Quran. The same activity needs to be done with Sunnah at times, the whole Sunnah is present within Muslim Ummah, but sometimes it gets adulterated by a group of people, so we need do the same exercise to make them realize the point of initiation of their mistake. Most of the times it’s just a little realization of this fact that you’ve to give to people, and when they look back, they agree with itma and Tawatur status of both Quran & Sunnah. In my experience, it’s the equal religious status of Fiqh & Akhbar-i-Ahad with Quran & Sunnah that sometimes mix things up and clouds our judgement.