If the seller sets their listings to be shipped to the US, and they are counterfeit, then they are not allowed to be listed on eBay, regardless if their local eBay allows them.
That policy needs to be enforced because the sellers are "criminals" in our sight and therefore they are unlikely to self police. So who exactly enforces that policy?
Right now sellers of NF items can post their goods as long as they restrict sales to exclude the US. So that works - right? WRONG.
I have tested the "no shipping to the US provisions". I ask the seller, "If I win will you ship to the US?" You will get the answer "Of course." There is nothing to stop the seller from shipping anywhere after the sale is complete. So the policy in place does not work.
You also say:
I am unaware of any eBay site that allows counterfeit coins.
Check France and Spain for auctions that can not ship to the US. You will find them there. Even the CWC could not stop French and Spanish auctions because of push back.
The policy at eBay sounds simple enough in theory but does not work in practice. The reason is that forgery (NF) is a large organized business pulling in hundreds of millions of dollars a year. They the forgers operate to make money and they have lawyers. eBay actually was coerced to operate on the let the buyer beware principle
or face lawsuit. That was because if eBay claims to have the ability to discern a NF from a genuine coin they can legally be treated as an auctioneer. That implicates them in the liability for fraudulent sales. That is why eBay now insists that they have ABSOLUTELY NO ABILITY to judge the authenticity of items placed for sale. They could but choose not to for self protection. They also will at their own cost refund the price for the purchase of a fraudulent item via their guarantee policy.
Another reason why the simplicity of the eBay policy is doomed to fail is because of terminology. The policy refers to "counterfeit" items but includes within their definition the legal as well as the illegal (fraudulent types). If eBay did have a working policy to stop posting of counerfeits (using their own definition) - it would have to include ancient fourees even the versions slabbed by NGC
also all of the Machin Mills coins, Non-Regal UK coppers, the Canadian Blacksmith tokens as well as all Contemporary Circulating Counterfeit (CCC). All of these coins legal or not would have to be terminated. (The legal CCC coins are all allowed by ANA
rules as long as they are properly described so there is no fraud).
The problem today in the world of coin collecting is Numismatic Forgery not the various types of CCC's. Numismatic Forgeries (NF) are/were made recently to fool collectors and defraud them. Older non-monetary items made while the originals were circulating (particularly those that circulated in the US before 1857) are collectable and completely legal.
Remember that the Coin Watch Committee initially was created with input from the ANA
and others to try to curtail or at least reduce fraud on eBay.
That committee did not work out because of the threat of lawsuits from the well financed forgers operating in China and elsewhere. The CWC had reduced fraud several percentage points while allowing most CCC's to post uninhibited provided they were correctly identified.
Now on eBay items can be reported by individuals or by certain key players like Bobby. The coins reported are by in large removed. But under the law the seller has equal rights with the reporting party and if the seller chooses to dispute the claim of fraud eBay would have to make a decision. The question is;
BASED ON WHAT does eBay make the decision?
With no experts on staff and no other in house expertise eBay can not make the call. If they do they face the same legal issues as when the CWC existed.
The forgers have for the present adopted a "no complaint" position because they have a few items removed but their bottom line is not harmed. Their identities are not terminated and related identities are also not sanctioned. More fake coins sell than get terminated as it stands.
If that changed and the forgers started loosing money instead (as they apparently did when the CWG existed) the threats would return.
So I stand by my comment that the only way to stop fraud is to stop buying frauds by educating the buying public.
With no sales the forgers would stop.