That removes the Nirvana adjacent for comparison as well as saṃsāra there must be evil. Otherwise, it does not know what is good, however, and there is no meaning if there is no evil is a comparative.
The next round of existences in order to attain such a comparison must be evil. Not so good, however, and it was not known to have no meaning. If there is a double advantage.
To get attached to the cycle of birth and death compared to Nirvana, such as good to evil. Otherwise it won"t know how well and have no meaning. If there is no evil, a pair of advantage.