See them on eBay but don’t want to get a fake.
Just be sure you know what to look for. There are communities of people dedicated to finding this stuff. (Like me!)
As for where they all went? A good majority probably got sent to a liquidation service like
@itsLouieV mentioned. These services will bundle them into pallets with other similar accessories and get sold to the highest bidder. TJX, the parent company behind TJ Maxx, Marshall's & Homegoods (TK Maxx too outside of the US) is a pretty prominent buyer of these, as we've been having fun finding OEM bands like the 2021 International Sport Loops marked down in their stores as low as $12.99.
The ones that didn't get liquidated (open box returns, demos, QC samples and the likes) were more likely sent back to China for destruction, where they often slip onto secondhand marketplaces and international sellers like Chargerstore on eBay will offer them for sale.