I didn't find uniwersal answer for this so I'm asking you guys.
Scenarios: 1. Vendor is good and trusted. Buyer is new. Buyer claims that he got nothing. 2. Both vendor and buyer are fine. Like above buyer claims that he got nothing. 3. Vendor is new and buyer has some reputation.
How do you think it should be resolved? From perspective of buyer you have 2 options: he did not get it or he did and he is lying.
And vendor always (even good vendor may do this as 1 in 10-20 packages) claims that it was shipped.
You are not oracle and believe in people - vendor's sent it, buyer is not lying about not receiving. What to do?
At the end of the day this question is one for the market admins to decide. Are you asking how the admins will tend to rule? Or are you asking in an ideal world of perfect information how it should ethically be resolved?
In an ideal world where everyone is honest and transparent, I believe it is the vendors responsibility to get the pack in your hands, delivered. Exception is if vendor states a policy to the contrary on their profile page Bc by purchasing from a vendor you are implicitly agreeing with their policies. Absent any explicit policy, a vendor is responsible for the pack up until moment it's marked delivered IMO. So a seizure should be vendors responsibility and he should refund or reship.
Now some exceptions. If you do something funny with your address - such as order to a vacant home - that's the buyers responsibility. If the buyer doesn't control the drop, that's on the buyer and at buyers risk.
Now what if USPS just totally loses the pack? Not returned to sender and not delievered? That's gray I think. Personally I'd be fine with a 50/50 split on this if I feel the vendor shipped in good faith. But I do tend to believe that getting it delievered is usually on the vendor and that's their responsibility so a reship or complete refund is reasonable. But I accept that there is risk to the game and shit happens thus why personally I'm fine with a 50/50 split in those cases. Esp for a good vendor I've done a lot of bugs from.
Reputation really doesn't change what should happen. It's a reflection that we operate in a world of incomplete information and dishonesty. Rep is really just used to help determine who is telling the truth. For instance, a new buyer shouldn't be penalized simply Bc they are a new buyer, theoretically speaking. However in the real world, they will be Bc it's one of the very few data points that can be used to determine who is telling the truth and who is right. That's one reason why selective scamming is notoriously difficult to stop and identify early.
These are just my academic thoughts. Each vendor and market treats it differently and you'd need to talk in specifics to get a specific answer. Hope this helps