Why do Unity animations look so bad?

When compared to Unreal Engine humanoid characters, why do the animations in unity look so bad? Like, you’ll make a blendtree with different movesets for a walk cycle, but it never looks natural. The poses blend unrealistically between each other, and look very robotic and like the character doesn’t belong in the game environment.
The animations have those generic indie game look.
In Unreal Engine, even if you don’t use motion matching, the humaonid animations look amazing, i don’t know how to describe it.
Is this a problem with Unity’s animation system, or just the quality of the animations of Unity users vs Unreal Engine users?