world quests also downgrade your delve loot in the vault as world quests count as a tier one and it operates by lowest level content rather than highest that week. Do WQ at your own risk but yeah radiant echoes are a good way to farm the shards just sucks you only get those from bountiful boxes which require keys. Such a dumb system they should remove world quests from the vault entirely so i can farm my keys without worry of my delve progress being ruined in the vault