I'm an Asian and I have double eyelids. It does makes my eyes look bigger compared to my other Asian friends who has monolids. But I don't think anything is wrong with monolids at all. I think they look very unique. Besides, having double eyelids just means I have eyelids that's a little bit more saggy. Haha.
I have an aunt who went for a surgery to get the double eyelid look. But as she grew older, the creases increased and her eyelids looked so saggy and loose it makes her look older than she really was so she went and have another surgery to fix it back to monolid.