I also wash all my fabrics when they come home with me.
I also wash my finished quilt. The batting will shrink causing the dimple effect in the quilt.
I do a lot of hand applique, so the last one I was using the card of bias binding for the flower stems, I first thought I wouldn't wash it but decided I better do it. The binding did draw up. So if I hadn't washed it, my quilt would of been ruined after washing it.