“Life isn’t fair” always bothered me, even as a kid, because it was used against me to dismiss unjust actions.
Saying something isn’t fair is basically saying it’s not right, it’s not just.
Trying to claim the injustice against me is moot or unimportant just because there’s lots of injustice in the world, seems bonkers to me.
I used to say this when I was a cringy 20-year-old, before I really saw and understood the world (and still believed in a god).