Your argument is that this method is not "failproof" due to "worshiping images" and that therefore it should be rejected altogether so that the best is if everyone believes what they feel led to believe and not care about commentaries. The output of your method disproves it, as it says "By their fruits ye shall know them". Tons of sects with mutually exclusive teachings or so called "damnable heresies".
I didn't say to reject councils, theologians, confessions, catechisms, teachers etc. We can consult them as part of our studies, knowing they are fallible opinions of men. Only the words of God are infallible, even though our interpretation is fallible. If 100 men agree on a lie to be truth, is it truth?
If I'm convinced of my own mind from reading Scripture that icons/statues veneration or credo/pedobaptism is blasphemous to God, should I ignore my conscience and do what a council of men agreed on?