Opinions differ, it seems.
You might find out what works for you, and what doesn’t. Find your own route to improvement. Accepting that certainty doesn’t exist.
You could also decide to follow one school of thought and ignore all others. That will give you certainty, though it’ll only be a feeling of certainty, no real certainty.
Just decide what attracts you most. Only you can make that decision, and you can only decide for yourself, not for others.