The % of 3star 4 star and 5 star do not go up with the blue  or purple summon  at all, they are the  exact same!  You go to the trouble of getting the the higher summon stone and it is useless!  Needs to be fixed as it it a waste of time

Uh, yes, everybody is aware... the point of the purple shards is not to have higher percentages, but that they only summon champions of the void affinity. Void champions don't have advantage/disadvantage against any other affinity and are supposed to be stronger in general. In practice, that's absolutely the case for some, many of the best champions in the game are indeed void, but there are too many useless void rares. 

The thing is that void shards are not superior to anceints. Its a shard for different heroes that have generally better stats. You are associating color of the shard with rarity. Understand that is a deceptive strategy that your mind tricked you into thinking color equals rarer champions.