I would rather stay ignorant than have to enter in confrontation. Likewise, I would rather veil the truth than to hurt another person. This is, of course, situational and not absolute. A good example would be cheating on an significant other. Saying otherwise would not be a white lie by any measure. If, for instance, your grandmother writhed in agony as the chemotherapy coursed through her veins, and she died from shock, I would much rather hear "She passed away in her sleep while on heavy pain medication". This would create easier closure, and dwelling on the opposite outcome could cause unnecessary emotional trauma.
I often think if we did not do so the amount of damage done would be incredible . How often had you to tell a white lie to save someone's feelings , I know I certainly have . I often think it's the word "lie" makes it feel extra bad for some people because it's a constant instruction from parents to kids growing up , so it's seen as bad because kids have to learn through experience as they grow when to lie and when not to .
White lies are generally a benefit to the liar, by avoiding an uncomfortable discussion about the truth.
In the rare case that the lie is told to spare injury, you are keeping a weak person from growing stronger and stealing their opportunity to face a flaw within themselves and overcome it.