I had a teacher when I first started out. I then spent more than 20 years without a teacher. During the time without an instructor I would sometimes challenge myself to learn a song and I would accomplish it but I didn’t advance much in skill. I’ve started taking lessons (remote over zoom) again for the past few months and am making much faster process. A good teacher will catch your blind spots and give a rational approach to new challenges. There’s a minority of people that can be very successful at learning musical technique without help. I would argue that the “right” instructor would more often than not get them to their destination faster.Are you self-learner or have a teacher?