I also think this card is a bit underplayed
It's one of the best Pokemon in Sun & Moon's sets, with several appearances in the Alolanthemed cards

Fish Tribal Creature (36) 1x Ancient Carp 1x Brass Herald 1x Burnished Hart 1x Callaphe, Beloved of the Sea 1x Cloud Manta 1x Dandan 1x Fleet Swallower 1x Gigantoplasm 1x Island Fish Jasconius 1x Jace's Mindseeker 1x Kapsho Kitefins 1x Manta Ray 1x Marjhan 1x Moat Piranhas 1x Mulldrifter 1x Pearl Lake Ancient 1x School of Piranha 1x Scourge of Fleets 1x Seasinger 1x Shipbreaker Kraken 1x Shipwreck Moray 1x Skitter Eel 1x Sky-Eel School 1x Slipstream Eel 1x Spawnbroker 1x Stinging Lionfish 1x Stormtide Leviathan 1x Thassa, God of the Sea 1x Thryx, the Sudden Storm 1x Tidal Barracuda 1x Tidal Warrior 1x Tideforce Elemental 1x Tolarian Kraken 1x Waker of Waves 1x Wavebreak Hippocamp 1x Windrider Eel Instant (11) 1x Cackling Counterpart 1x Counterspell 1x Cyclonic Rift 1x Dissolve 1x Engulf the Shore 1x High Tide 1x Mind Games 1x Rain of Revelation 1x Shifting Borders 1x Stream of Consciousness 1x Whim of Volrath Enchantment (8) 1x Dream Tides 1x Eel Umbra 1x Fishliver Oil 1x Flood 1x Homarid Spawning Bed 1x In Bolas's Clutches 1x Leyline of Anticipation 1x Mystic Remora Artifact (3) Commander (1) Land (37) Sorcery (4) Suggestions Updates Add Comments Attention

Its hard to say for sure, but we can make a deduction based on a few assumptions
Overall, graveyard-based strategies have become popular, as many players now aim to return Arclight Phoenix, Cauldron Familiar, or Parhelion II from the graveyard
Dont worry, that compartment is removable