Champion Shards

So why do we get champion shards if we own all the champs? It seems kind of pointless/aggravating when you play a lot of games to finally get your 3rd key fragment only to get a champion shard for a champion even though you own every one of them. I get that it's free and yes I do appreciate it but what's the point of getting something you own and you can't even do anything with it? I also have enough IP to buy any new champions when they come out so there's no point in me using the chests to get new champions. Does Riot have something planned to change this? I wouldn't care about the key drop rate as much if the chests didn't keep dropping me champion shards which have 0 use to me since you can't even use the blue essence for skins.