Note that our minds are massively parallel calculators that don't necessarily require language, yet our instructions are sequential and language-based.

Not all teaching is sequential and/or language based. It's just the most popular way to teach. Especially for people who believe that reductionism is useful.

NLP (Neuro-linguistic programming) is for example not taught in a sequentlial fashion if you learn it from Richard Bandler or students of Bandler.

That makes conversations about whether it's backed up by scientific evidence hard, because the idea of science is that you can test sequential step to see if they work.