Perfection as we all know is a mirage. It's not real. There is no perfect in the real world. For every living organism there are faults. Some say that the beauty is in the faults. Perfectionism is in the eye of the beholder. Therefore it's entirely dependent on an external filter. An object's inherent beauty comes from the beholder and not the object itself. Some people find beauty in the most odd things. The things you find beautiful and perfect may be horrible to someone else. Some like rock, some like classical. Some people find noise beautiful some love the sound of the violin. It's all in the eye of the beholder.
There is a difference when you are the creator. In this way you have control over the 'beauty' of the object. In this way, there is the tendency or at least there is the option that you can always make the object 'more beautiful' or 'just better'. If the goal is to make the object or outcome as good as possible, what's the problem?
The problem is perfect is imaginary. The perfect object or creation doesn't exist. More importantly, what seems perfect today can appear to be imperfect tomorrow. To some there is the idea that no matter what, any object can be improved and 'made better'. In this way the creation is actually never done. It's never good enough. It never sees the light of day. There are some creators that do let their work out into the world. Yet for perfectionists, the work still isn't done. The work is never done. Even when the world has declared their love for the creation, the work still isn't done.
The worst side of this is when the work never gets done. The work never actually becomes good enough for public consumption. This is the biggest pitfall of perfectionism. The work is never good enough.
Being a perfectionist is supposed to help the artist in the creative process. It helps artists separate the great from the crap. It makes them question what they have created and wonder if there is a better way. If this helps make the art better, then it's a good thing. If it stops the art from ever getting finished, it's a bad thing. If it comes to the point where the artist no longer creates, then this is the worst thing.
In actuality, it is true that a lot of works could be improved upon. There are works earlier in an artists career that don't stand up to their later works. There are points in every artists careers where the work isn't as good as others. This is all part of the process. That's the point. You must create these 'points' or works of art to signify your progress. If you've created something and it's not up to your standards, ask yourself why. Look at your art and see how you can improve and what you may have done wrong. Do you lack talent, need more training, or need more time on that particular skill?
Whatever you do, don't throw it away. It's there to teach you something. It's part of your journey. If you're assessing something right after it's been completed, are you being completely impartial to what you're seeing (hearing)? Finish it, wait a while and then look upon it with fresh eyes. Can you make some minor adjustments? Is it good for what it is? Is it a major piece/accomplishment or another step in your development?
If perfectionism keeps you on top of your game. If it's responsible for your high level of creativity, then that's great. If it's getting in the way; stopping you from creating, making projects take years instead of weeks, stopping you from being happy with your art, then lose it. Lose it now.
Create it, critique it, edit it, finish it, move on.