> that Paypal is shielding them or insuring their purchase in some way

this is absolutely the case for me, multiple times I had a great experience getting refunds with PayPal and multiple times I regretted not purchasing something using PayPal because getting a refund was much harder.

I now use PayPal exclusively for any online purchase > $500 precisely for this reason[1].

[1] unless it's a vendor that I know has a good return policy, such as JB HiFi.