Amazon is abusing it's monopoly power to hurt competition, when Amazon is the only place to certain things, consumer cost will go up.
No seller is obligated to sell on Amazon to begin with, so this entire premise is false.
Clearly the FTC disagrees with your logic, and I'm glad they do. FedEx, UPS and USPS should be sued too if they did what Amazon is doing.
If the FTC doesn't get them, rest easy. At least Europe knows how to keep their market on a leash.