I feel like the Key Fragment drop rate isn't equal to Chest rate.

If I'm getting 3 chests for every 2-3 key fragments I will have too many chests and not enough keys. I understand the chest rate should go down in theory with the more champions you get S on but I don't think it will because it takes ~2 weeks to get a key while it takes 1 week to get a chest and all you have to do is carry with a champion you don't play much? It's very off. I just went 2 weeks without a key fragment btw but I know I'm not unlucky because my friends and people on Youtube complain about the same thing :/

I hope this gets updated or else nobody will buy chests with RP only keys/chests+Key bundles and buying JUST chests would be a waste of RP.