your logic seems incorrect to me. The fact that only a handful of people get the certificate doesn't necessarily mean the certificate itself is useful.
can't say anything about CPA but I don't know any people in financial industry here (NY) with CPA. I thought it is just for accounting people.
CFA is absolutely useless to investment banking/PE/Most Hedge Fund. Kind of useful to asset management and equity research area. Some asset managers do require employee finish CFA in a couple of years.