As far as I understand they drop instead of key frags and contain the same amount of key frags you'd get anyways, so whatever it is there is supposed to be some kind of bonus. I do agree that the "bonus" feels underwhelming, given how rare these arrive. I've got like 3 or 4 (almost sure they are 3, but not entirely) I have no right to complain, as I got Grey WW in the last one, but yeah, the ones before that were pretty disappointing. At least before we could disenchant 3 shards into a random champion so even getting kayle and nunu wasn't that bad, but now it's meh. I think the prizes should be higher not because "give us more stuff RITO", but rather because that it is a reward for a positive play and if it is feels underwhelming it barely helps to reduce toxicity.