The eBay/PayPal split has been a mess. eBay should have had its own, seamlessly integrated payments from the start, but lacking that PayPal was a good crutch.
Since the split, you now get the choice of paying through eBay directly, through PayPal, or another way (depending on what the seller accepts). Simplifying this for small dollar transactions is critical if eBay is to stay competitive with Etsy, Amazon, Target, Walmart and the numerous others that are sharing the online shopping market.