In case of a dispute, the seller has to provide proof that the item was delivered. Delivery confirmation (such as from USPS, FedEx, USPS, etc.) provides that proof for most cases. If you are not 100% sure of the person you're dealing with, then signature confirmation might be an extra step to take but is not absolutely required in case of a dispute. Furthermore, there is always the chance that the item does not arrive in the condition stated, the contents were damaged or even missing altogether. To protect the seller, insurance is highly recommended but not required. The seller should be willing to work things out with the buyer in case there are issues.
There will always be exceptions to the rule and we will treat each case on an individual basis while making every attempt to be fair and impartial.