I've gotten scammed both times I used paypal recently, and paypal didn't do squat about it.
Why?
Because both times, the seller shipped something and it was delivered.
The first time, they shipped a small piece of plastic in a small envelope instead of a bunch of brushes for our robot vacuum (basically $0.05 value vs $150 value).
The second seller shipped who-knows-what to my city/zip, but when I went into the post office to see where the F the package was delivered (because it came up as delivered on the tracking), it was delivered - properly - to a different address. In other words, they sent something to an address that would make be believe it was on its way to me, and it got delivered. Not to me.
Paypal? Both times they say that delivery was made, and I'm out the money.
I bounced both through my USAA credit card and got my money back, but I'm completely done with paypal.
I've since singed up for the USPS "Informed Delivery" so I can see what's on its way to my address, but this won't help if a scammer sends me an empty box or a package with worthless crap in it because paypal will just say "you got something, be happy".