A will only takes effect once the person making the will has died. An LPA also remains passive until triggered, but this legal document becomes live when the donor loses mental capacity – that may never happen, whereas death is a certainty!
An LPA doesn’t overlap with a will, so it won’t affect what happens once someone has died. Either the deceased’s assets are distributed in line with their will or, if they haven’t made a will, then following the laws of intestacy, which determine who gets what.