I think it’s mostly nostalgia, and the fact that it was kind of the first iteration of the design all controllers use now. The 360 controller was good but it was really only the start. In my opinion each xbox controller has been a massive improvement over the last.
The series x controller is probably the most well refined controller I’ve used, and the only reason it’s not my pick for best controller is because I’m a sucker for all the fancy tricks of the dualsense.
I used to hate playstation controllers because they always felt really weird to hold. Even the PS4 controller was terrible for me. With the Dualsense PS5 controller though they just made it an xbox controller with playstation gimmicks and that was such a great move! It doesn’t look too ugly either, since it’s just the same basic shape as an xbox controller. It doesn’t have the nice weight that an xbox controller has and I definitely prefer the joystick layout on xbox, but the haptic triggers, the hd rumble, the trackpad, and the gyro sensor are all things I don’t think I can do without anymore!