Design be perfect, because you actually have a chance to do so. Design is declarative. You are defining what be. People who are studying someone's design specification shouldn't have to wonder whether your circle is a circle. A designer declares a perfect circle even if when zoomed in you find bumpy pixels.
Also, design in the context of a team especially ought be perfect, because your perfection will be degraded in a game of telephone.
By perfect, I don't mean that your design fits the user with maximum optimality. I mean that when you draw a box, you actually mean a perfect box. When a mathematician draws a square, they are describing a perfect square. It would be a little socially blind to pick up a magnifying glass and accuse the mathematician or the designer's square to be imperfect because you find the bumpy ugliness of a 1080p monitor or a sheet of paper.