package insurance as a seller: lemme get this straight

So the buyer pays shipping for a listing

They select an uninsured shipping option covering only 100$, with a notoriously unreliable carrier

As a seller I have to pay for the other half of shipping to add signature / insurance or I end up holding the bill if the carrier loses it per ebay’s buyer guarantee?

If the buyer pays and selects shipping and my item’s size material and weight is correctly documented, is it not only my responsibility to get the item to the carrier?

That’s the equivalent of me hand delivering a purchased item to a neighbor, they say “yeah I got it leave it on the doormat” and later they invoice me for a porch pirate getting it because they couldn’t be bothered to make sure someone was home.

If my car explodes on my way to their house and I never make it to the door that’s on me, why the heck am I paying for shipping for an item the buyer explicitly pays for shipping?

How have yall’s experiences been lately when it comes to carrier insurance for expensive items?