While some people are able to independently educate themselves through various means for the vast majority it's better to have a teacher guiding them, most people like motivation or enough direction to be able to teach themselves the necessary skills and fundamentals of a subject and a teachers main job is ensuring that they do.
It's always better to have a teacher when you are trying to learn something new.They can get you through stumbling blocks or offer a new perspective.When you are discouraged because the subject becomes very challenging a good teacher can encourage you with words that make the challenging interesting and exciting again.
Teachers are an important part of the learning process. If teachers were not necessary, there would not be so many in schools. Students can work independently sometimes, but it is necessary for them to learn from someone with experience. Students need to be able to ask questions if they cannot understand the material.
It is better to have a teacher, because the teacher can teach you what they have already learned. When you are learning how to do something, practice only makes permanent. It is perfect practice that makes permanent. A teacher can help someone correct mistakes before they become ingrained habits that are hard to break.
In the beginning, it is beneficial for a teacher to lead you through your problems, however, once you know enough about a subject, I believe you learn much faster by experiencing things for yourself. Programming and 3D modelling are both very good examples of this. You have to learn how to apply your knowledge yourself once you've learned the basics.
I post on the no side, but in all reality I am on the fence. Blended approaches based on the subject matter and the experience of the students work best. Some subject matter is better instructed, other self-led.
In addition, real learning happens best with engagement on both sides. A teacher to guide, a student self motivated doing a complement of self study, to get the strongest approach.
Technically you could "homeschool" yourself. People do this for a multitude of reasons like mental or physical issues that make it hard to go to school and learn. Also, if you do things yourself and do it correctly, you have more pride and want to do more. That's why it's better to do things on your own.
I personally learn more when I'm teaching myself. I do better when I'm having online courses instead of face to face courses simply because I think it is good to experience things for yourself and to learn from your mistakes and to teach yourself. I think you are limited when you have a teacher but when you are teaching yourself the possibilities are endless.