A mesorah doesn’t add to the integrity of torah, it is merely the transmission vehicle; it was meant to be transmitted from rebbe to talmid, father to son, in both content and methodology. Those are things you need a mesorah for; to know a good sevara from a crooked one, to know what the kavanos of chazal, rishonim etc were, it’s not about proving the Torah or adding credibility, it’s about getting the tools necessary to understand something that all along was based on a handed down tradition. When the mishnah was completed, it was cryptic and needed the gemara to explain it; when the gemara was written, it would have been a closed book if not for the rishonim; he rishonim thensleves are very perplexing and are constantly studied over by the achronim and ourselves…someone without a mesorah cannot approach these matters because they simply don’t have the tools.
That doesn’t mean you have to blindly accept the particulars of what you’re taught; rashi argues with his rebbeim quite a lot, and tosfos argues on rashi on almost every daf. But those are in the details; tosfos doesn’t say that rashus entire approach was wrong and that they are inventing a new mahalach in torah ex nihilo.
I know from my own years in yeshiva that had i not had intensive blatt shiurim id never be able to understand rishonim; i could try on my own, but it would have been a colossal failure….the worst part of which would be the fact that i wouldn’t be aware of how much of a failure it is
Maysoh bereshis/merkava also was passed down without being written as per the rambam and other rishonim, for another example.
And just what “great torah sages” are you getting this from? Do they have recorded torahs echoing your sentiment? Or is it “mesorah”? Or is it people who you consider torah sages, but are considered heretics by people like rav shlomo zalman (re, kapach) or the chazon ish (re, liberman), or rav shach and the steipler(re, steinsaltz)?