It’s a Style Thing.
I’ve mentioned this idea before - that there are many “streams” of art practice in the painting field. Let me put it to you this way…
Think about the martial arts… you have t’ai chi, kung fu, karate, judo, aikido, Thai kickboxing, cage fighting, krav maga, and many more (that’s a lot already). They’re all (more or less) focused on one goal, and that’s how to develop a practitioner’s skills in fighting, or rather defending against, another human. Each has a different approach to utilizing the body’s structure, its functions, and physics. Some are purely about how to block, evade and strike, others purely about body movement, some combine the two. Almost every video I’ve seen “comparing” the effectiveness of each has been fraught with fallacies and poor experimental methods. And in trying to “prove” an art’s effectiveness, they don’t account for the fact that a practitioner of one art might be a superb exemplar of it whereas the other might for whatever reason be a relatively poor one (size, flexibility, genes).
On top of that, each develops its own “lore” - ideas unique to each one’s specific culture and way of thinking. Some stick to purely physical goals and methods, some go more into psychology and others go completely metaphysical, delving into mysticism. Most regard their method as a way of life to some extent.
Anyway, the point is - they’re all different ways to the same end. But one thing I can say with certainty (since I’ve been there) - almost every practitioner will believe that their particular art is the most effective of all of them and will trot out many reasons why. Or they will have trained in a couple and will create a hybrid that they claim overcomes the limitations of what they studied before. And it’s understandable, given the (literal) blood, toil, tears and sweat that they will have put into their training for many years.
As far as I can tell, it’s the same in the art world. You have all the “movements” that have characterized art, most being called names that end in “-ism”. They have all been characterized by features and techniques that captured the collective imagination of their time. Many proponents are fanatically loyal to their style, possibly because of (again) the toil, tears and sweat (maybe not blood!) that they put into it. Some will study a few and create their own, which - you guessed it - they claim overcomes the limitations of what they studied before. And they will practise and even teach their art style as though there aren’t any others in the world. I don’t mean any of this as a negative criticism, but rather an observation of how it all naturally works.
My particular interest is in realism - capturing the world as I see it to be with paint. But even within that there are different approaches - some take a “painterly” approach using loose brushwork that in any other context would be called untidy. Others favour much tighter expression and produce “neater” artwork, while still others are not content with anything less than photo-identical painted images. All three approaches produce images that are undeniably captivating and beautiful, and each requires immense skill. None of them can be called “better” or “more” effective than any other. They are simply a distilled expression of the artist’s instinct, training and experience with paint.
So beware artistic advice that is dogmatic. Or rather, understand where it’s coming from. It’s most likely correct, but in a specific context. Try to understand what that teacher is focused on in their art so that you can ultimately combine it with something you learn elsewhere and synthesize a style that is uniquely yours. There are certain technical basics that are universal, but how they’re balanced and prioritized against each other is what determines how your work will ultimately look.