Why the -300ER is Boeing's Best-Selling 777 Variant

Since its maiden flight in 2003, the Boeing 777-300ER has become the best-selling variant of the Boeing 777 family. As of 2020, over 830 777-300ERs had been delivered to operators all around the world. Why is this? What made the 777-300ER so successful? (aeroxplorer.com) 기타...