Luke is like, living proof that the old Jedi ways do not work; he was trained when he was in his 20s, not raised from early childhood, so everything he did was based on his own moral compass, not doctrine drilled into him from an age where he’d have no concept of understanding it. Yoda and Obi Wan basically relied on faith that he would choose to do the right thing. the ultimate irony of the prequels really is that Anakin was too young for that, not too old