Avoidance has a approach/repel dynamic. You are attracted to it because you want the reward, but repelled by it because you think it's difficult. "Don't spare the rod" parenting, beats children until they stop avoiding things (ie., an approach-side policy: encourage approach). You can also break tasks down, make them less core to your identity, rewards etc. (repl-side policy: make it less repulsive).
A lot of people try the approach-side policies, and beat themselves up, etc. which works sometimes but not always. "Perfectionism" is often caused when people beat themselves up to do something thereby making that very thing seem even more difficult/essential/important/etc. which makes it even more repulsive.
"Perfection" is the propaganda of a mind doing everything it can to avoid a task, often also caused, by pathological demand avoidance wherein avoidance can become extremely elaborate in justification to the point of apparent delusion.
Ignore all this superficial language. The heart of the behaviour is in what isnt being done; that's the truth of what's going on.