The point of the hook statement "You are not a visual learner" in the Veritasium video is not to "disprove the myth that you're a visual learner."
The point is that there's little evidence behind different people having different learning styles, and that in general everyone is every "style".
This implies that vision, in addition to many other sensory modalities, is useful. As you point out, the utility of of 3b1b is in line with this point.
Just chiming in to say that you can dive directly into Strang's Youtube lecture series, without a book or anything else; like, an immediate next step you could take if you wanted to is just to pull up his first lecture right now and watch it. (I mostly watched him at 2.5x speed).
The point is that there's little evidence behind different people having different learning styles, and that in general everyone is every "style".
This implies that vision, in addition to many other sensory modalities, is useful. As you point out, the utility of of 3b1b is in line with this point.