Does it get registered somewhere official?
Let's say there's a married couple (or a parent / child). One dies, the other one knows there's a will in the desk upstairs. Opens it and the dead person has left most of their assets to the donkey sanctuary. Alive person tears up the will and pretends there was no will in the first place so they can inherit under intestacy rules - could this happen?!
Or if its kept by a solicitor, but the alive person doesn't know this, or deliberately doesn't tell the solicitor when the other person dies.
I've always wondered...put me out of my misery!