to identify with alchemy at this juncture is implicating a set of beliefs, based on a handful of cherrypicked actual alchemical texts and guys like Jung who use alchemy as a metaphor for internal change that doesn't map at all historically to what alchemy was, which was proto-chemistry first and anything else second, but is something modern people looking back on tend to incorporate into their understanding of it.

But the title of that video just means that guy has read paracelsus and jung and wants to talk about FMA lore as it maps onto our actual extant literature on the matter.