The thing is, on paper, the game seems awesome: it's a lot grittier and darker than D3, combat and skills feel weighty, the character and armour design are cool too. However, there's just not a whole lot keeping you motivated long-term unless you're a fan of battlepasses as a form of carrot on a stick.
Enemies are way too tanky, you essentially do not feel your character getting stronger because the entire world scales with your level, the skill tree is not as deep as it seems on a surface level...
I could keep going with this. Point is, the amount of monthly recurring players speaks for itself.