WInglet is not uncommon in China since commercial jets with winglets have been operating in China for many decades. There are many ways to design wings of good aeredynamic efficiency other than adding winglets. They have their own conclusion and reason not to add winglet on Y20 which we are not told.
The Y-20 transport aircraft does not specifically use its wingtip to create turbulence for aerodynamic efficiency like winglets do. Instead, the Y-20 features advanced aerodynamic designs, including a supercritical airfoil, to enhance its efficiency. Winglets are designed to reduce drag by minimizing wingtip vortices, which improves fuel efficiency and stability. While the Y-20 incorporates various technologies to optimize performance, it doesn't specifically use wingtip turbulence in the same way as winglets. - AI Reply.