The loot system is based in mechanics which contradict each other's effeciency

If you want chests, the best way to get them is with premade groups since everyone can get a chest if just one of you does. This is nice and all and helps promote playing as a team with your friends.

However

If you want key fragments/keys, you are better off playing solo since premades do not benefit from honoring each other as well as other players outside of their group can. This promotes solo play where being good as an individual (in both skill and interactions with team members, is promoted.

Now, while it is still possible to get chests as a solo and key fragments as a premade, it is much, much harder to do so. To me this is a bit frustrating since I mainly play solo. And while I am not rolling in the key fragments, I am finding that getting chests is much harder than getting keys, which also are not that easy to come by since you need 3 fragments per key.