Meaning and correct use of "as to why"

Let’s break it down. “As to” is synonymous with “regarding”, “concerning” or “with respect to”. In a real use case (news headline):

Here's A Quick Explanation As To Why Today's Jobs Number Made No Sense

It doesn’t add much meaning in “as to why” compared to “why”, except for sounding more pedantic.

I don't think "as to why" means anything more. It's a rather unusual term except in poetry where you need a bit more emphasis - or a couple of extra words to make the lines line up.

From Merriam-Webster:

as to (preposition)
1 : as for, about
2 : according to, by

Your example sentence with "as to" doesn't make much sense to me.