If adults "don't need" to drink milk and that includes the plant-based alternatives that this article is about, can that be extended to claiming that adults "do

If adults "don't need" to drink milk and that includes the plant-based alternatives that this article is about, can that be extended to claiming that adults "don't need" to eat almonds, oats, or soy? Is there something special that happens when those things are blended with plain water that renders the resulting liquid unsuitable for adults?