What are the advantages of using Shipstation over direct Shopify fulfillment?

Hello,

We currently use shipstation to fulfill and ship our orders. We used to use them for returns as well, but our returns portal has been broken for almost a year with no planned resolution. I am wondering what the benefits are of paying for shipstation vs. fulfilling orders straight through shopify. We only receive order through our shopify store so we don’t need it for any other selling platforms. Any insight on this would be extremely helpful.

Jackie