Skeleton fleets should be way more profitable

...But they are?

1 round of skeleton fleet is enough to reach grade 5 for reaper and guild ship respectively.

Unless you're talking about the Raid voyage and not the normal world event, then yeah it should prob get some buffs on that.

@nasenbaer020210
100% agree that it is the world event that has the potential to be the most enjoyable. Ghost ships don't have dynamic movement so are easily predictable, and all the other cloud events are land based which don't provide any real threat towards your ship.

It is the most challenging as well, so the effort put forth can be very different from player to player. I can dive to one solo, spend less time fighting the first 2 waves of 1 skeleton sloop each than the time I'm spending retrieving the treasure from them, and then have the final skelleon down all in very little time. Faster than chasing ghost ships around an island, and faster than killing multiple waves of skellies followed by a skelly lord. The downtime waiting for the ships to sink really slows things down but sinking the ships can potentially be relativity easy and fast. My time and effort is minimal but all players will be different.

The treasure recieved from a normal fleet, I feel, is worth the time, effort, and risk. Some of that risk with the battle being right next to reaper's hideout and in the center of the world. It has several pieces of skeleton captain's chests and skulls, and while they are not exclusive to this event, it is the only place to get them without an element of chance. It's an excellent place to get supply crates, and it's great for pve reapers.

The amount of treasure recieved from diving to a skelly ship raid may feel a little low but I don't think that's the fault of the event itself but just the design in diving to raids. All of them feel like they lack in the amount of treasure to me, but that was actually a choice they made when they created them, to have less treasure, but more valuable and unique treasure.

This event can go quick, smooth, and provide a good amount of loot for the main three factions or reapers.
It can attract pvp which can increase the amount of skelly ships and potential loot spawned, literally increasing the risk and reward simultaneously, while creating an intense and chaotic naval battle with several ships fighting amongst each other.
It can be a great source of supplies you can collect passively while still earning treasure.
The entire event as a whole has a lot of unique value that isn't in the treasure specifically. The challenge is greater, other player interaction is more likely, the dynamic AI behavior and movement, adapting to the amount of player ships and ship types.

My only real criticism of the event is how slow the ships sink and disappear. Waiting for the loot is almost as bad as waiting for the treasuries to fill or drain water.

For me, the loot of an organic fleet is perfect for the effort and provide a quick rank V Reaper grade for pvp hunters. That's good.
The loot of the player generated one is terrible. It's good only for the 15k piece, the rest is underwhelming.