"For Faster Shipping, Items Are Commingled at Warehouses, Opening the Door to Knockoffs" (https://www.wsj.com/articles/on-amazon-pooled-merchandise-op...).
Basically if a third party seller says it's a "Genuine Apple iPhone Charger" (whether it is or not) and the packaging looks real enough, it gets thrown in with all the other sellers (including Amazon) who have genuine chargers.
Thus "sold by Amazon.com" means just what it says - "sold" by. Not "sourced" by...