We need to rely on a teacher. There's no way around it. Anyone who does not, should not engage in Tantras or Tibetan Form of Buddhism. To engage in the Tantras, guru devotion is supreme. I didn't make that up, that was Vajradhara's stipulation.
Other forms of Buddhism may seem independent of a teacher in the beginning, but not for the higher teachings.
Ashvagosha in his famous composition on the 50 VERSES of GURU DEVOTION makes it very clear the importance of our spiritual teacher. Even Je Tsongkapa's own works makes it very clear how important the guru is.
If we read Trijang Rinpoche's biography, his devotion to his guru was supreme and complete. He confessed sometimes he didn't understand why the guru would have commanded this or that and it was only very later he understood, but nevertheless, he followed respectfully.
These are good examples to follow.
TK