Perfectionism is not a problem in itself. If someone holds high standards for themselves, that is their prerogative. However, if they impose those high standards on their partner, that is often problematic.
There are basic standards in many relationships, such as telling the truth and consulting with your partner if a decision will impact them. However, if one expects perfectionism from oneself and then imposes these same standards on one’s partner, it creates judgment and criticism. A perfectionist can tell a partner how they would like something done but not insist the partner does it their way.