>BTW I think it’s utterly irrelevant whether someone “gets” PEMDAS or not. That’s not math. To the contrary, it belies a rote, formulaic way of thinking that is almost inimical to math.

Being able to "get" PEMDAS in particular doesn't matter. Being able to "get" things like PEMDAS matters a great deal. Understanding that there are rules that bind the squiggly lines on the page is an idea about as central to mathematics as any I know.