This is the same problem that BZ has where it seems that the leviathans just exist to scare you and slow you down
In subnautica the leviathans all felt like they really worked with the world and areas they were in, reefbacks were gentle within safe zones, reapers were in sparse areas and attracted to the crash, the ghost leviathans are born in the lost river and seek deeper waters, and the sea dragon dominates the lava castles.
But with SN2 and BZ they are just placed for fun and have no story around them, they force you to go through them because they just live there or whatever
The giant clam is kind of just placed somewhere, the deepwing brooders are weirdly rare, the collector stays in places where you are going to go, the Chelicaerate is the same as the collector, and the shadow leviathan is in an unbelievably cramped biome

The devs have said that the collector and possibly other leviathans are in temporary spots.

Its a difference between a game that tells a story and a universe, and a game that just collection the mechanics and content.
Could be just a case of building the gameplay first and then developing the lore to support their placement in the environment. I agree that this was more believable in S1 than in BZ.