When I search the ocean I can't find any fish, drowned or dolphin. The mobs barely spawn in the overworld. But in the nether and end there's many of them.
And the thing is, you can't get trident, phantoms attack you but they disapper after running 10 blocks from them, no polar bears, llamas, or rabbits other than sand variant.
Easy mobs:
You can one/two shot every mob from distance expect endermans. Mobs should have the random potion effect granted (strength etc.)
It's no challenge right here.
In the next revision plz buff mobs.