Is Friction conservative or non-conservative force?

I was studying that why friction is non-conservative force and I came to know that its work done in a closed path is not zero.

But, when a body moves in a loop then its initial and final positions are same so that displacement should also be zero. Then whatever the force or whatever the angle the work will be zero.

As friction work is negative to the motion but the displacement is zero. Then work will be also zero.