Sorry...but I don’t see the word *alone* in that quote anywhere.
I think all Christians agree that the Bible is an amazing, living source of teaching, inspired by God to assist us in following the WAY with Jesus...but I have never seen any Scripture that says it “alone* can teach/guide us. It does NOT say that the Bible is the pillar of truth for us either.
Doesn’t matter what Christians ‘agree’ on. Exercise volition, day to day, in a relationship that is one on one, and appreciate grace as much as possible.
It alone is the textbook (instructor needed) for life.
Your mileage may vary.