Anxiety
Two patterns that often show up as one.
Perfectionism often gets described as a strength in disguise, high standards, attention to detail. In practice, for a lot of people it functions as a way of managing anxiety, where the standard itself becomes a way of trying to control an uncertain outcome.
Anxiety about being judged or falling short drives the perfectionism. Meeting the standard brings brief relief, which reinforces the pattern, but the relief rarely lasts, since the next task resets the bar. Over time this can produce chronic overwork, procrastination out of fear of an imperfect start, or difficulty finishing things at all.
Addressing the anxiety underneath the standard tends to matter more than addressing the standard itself. That usually means looking at what falling short would actually mean to you, and where that meaning was first learned.