There's definitely value in wrapping APIs - an API is useless to someone who doesn't know any programming. If you can provide an easy interface for non programmers to use the service, that definitely has value, even if the API does all the actual work.
You should aim to have a way to switch on the fly between 3rd Party providers though. On my (small) e-commerce website the payment processor would occasionally have issues with a customer, so I had actually signed up for multiple services that I could switch between at any time. That was useful when one of the providers I'd signed up with ended up getting out of the consumer e-commerce space at short notice.