It functions that way. Forget the technical terms, as ebay uses their own concepts.
If you buy something and it is covered by buyer protection, the burden is on the seller to get it to you as described safely or ebay will not protect the seller in a dispute. And they better require a signature for proof of delivery, or they are naked. On a sizable purchase like a bicycle, otherwise would be foolish for the seller.
Overseas purchases are tricky of course due to the long transit times. If the buyer has not received the item within a month and files a dispute, "item not received" the seller will be on the hook, or the insurance carrier for the shipment. Sometimes things resolve themselves over time as the item shows up a few weeks later, sometimes not.

Domestic is much more straightforward of course.