They were equal, imo.

Kuruk, easily. The guy sacrificed his lifespan and legacy to preserve the saintly image and reputation of Yangchen, lost the love of his life, and he had to fight off dark spirits.

Azula's life was not easy by any stretch of the imagination, but Kuruk arguably had it worse.

Azula at least had the illusion of an easy life to fall back on, Kuruk was born in the tundra, finally got out of there, only to fight soul-sucking spirits on his own and die young.

Context of both pasts please. (WITH SPOILERS)