IS NON-EXISTENCE ALWAYS PREFERABLE TO EXISTENCE?

Now I speak to you as an existentialist philosopher: The non-existent exists, only that it exists in a non-existential or nonexistent way. So it is difficult to decide if non-existence is preferable to existence, since on the other hand existence can also be a nonexistent existence. In any case, if there were no other alternative, I would prefer existing existence.