The way loot drops are set up in Maelstrom Arena makes it basically impossible to complete the Stickerbook without grinding for dozens and dozens of hours.
In addition to the very useful and popular Maelstrom Arena 2-piece weapon sets, Maelstrom Arena drops 6 other less useful full 5-piece sets (Elemental Succession, Glorious Defender, Hunt Leader, Para Bellum, Permafrost, and Winterborn). Each of these 5-piece sets includes 13 separate weapons and 2 jewelry items. These 15 items from each of these 6 sets ONLY drop on the final chest of the Maelstrom Arena after killing the last boss.
This means that in order to fully farm the stickerbook for Maelstrom Arena, even with curated items drops, you have to clear Maelstrom Arena 90 times!!
Even if you farm it on normal at world record speed, you will still be required to spend dozen of hours repeating the same content over and over again.
The gear in Maelstrom Arena is uniquely difficult to farm for 2 main reasons.
First, Maelstrom Arena is the only content in the game that has 6 separate 5-piece sets. Dungeons only have 3 sets, Overland zones have 3, and Trials have 4. Not even other Arenas have 6 sets. Vatashran Hollows only has 3 sets, and Dragonstar has 4. Blackrose does not have any 5-piece sets (it just drops Overland gear from Murkmire).
Second, Maelstrom Arena is a SOLO Arena. That means there is absolutely zero chance of making farming easier by trading gear with other players. It is impossible to get the gear except as a single drop, one at a time, clearing.
I think the easiest way to fix this massive unnecessary grind would be to increase the drops of the weapons and jewelry for the Maelstrom Arena 5-piece sets. Even if Vatashran Hollows had 6 separate sets like Maelstrom Arena, it would still be a much better experience to farm. Vatashran Hollows will drop 4 different 5-piece weapon/jewelry items on each run (1 drop at the end of each of the 3 wings, and 1 drop from the final boss), while Maelstrom Arena only ever drops 1 single 5-piece weapon/jewelry item.
Maelstrom Arena drops should be set up in the same way as the Vatashran Hollows drops. Maybe every other boss could drop 5-piece weapons/jewelry, or maybe only the last 4 bosses could drop weapons/jewelry so players have to get further into the arena to farm. Either way, making these weapons/jewelry easier to get would not impact game balance since these sets are not particularly powerful or sought after, and the vast majority of players running Maelstrom Arena are there for the 2-piece weapons anyway. Increasing the drop rate on these 5-piece weapons would just make the game less tedious for those who want to finish the stickerbook.
ZOS please go back and make Maelstrom Arena loot less hellish for stickerbook enthusiasts! Or at the very least bring back the Maelstrom double drop event.