key drop rate is terrible

the drop rate decreases the more fragments you get until it's reset.

I for one agree with this. I probably will get only 5 keys in a month yet can gain about 2-3 chests per month.. Pretty bothering knowing I will just stack up on chests and I won't be able to open most without spending real money. The key drop rate doesn't reward players as much as it should. It should at the very least be able to keep up with the chest collecting.