It allowed him to forgive himself.
: Even after Shukaku was extracted from Gaara, the sand continued to protect him, proving its power came from his mother’s love rather than the tailed beast. did gaara's mother love him
Naruto Uzumaki saved Gaara from loneliness by offering friendship, but Karura saved Gaara from self-hatred by offering legitimacy. Learning that he was loved—not by a concept, but by a parent who sacrificed everything for him—allowed Gaara to transition from a weapon of the village to its leader. It allowed him to forgive himself