It's very common to wrap fascia boards with painted aluminum. While redoing an aging roof recently it became apparent that by doing this you could be prolonging damage not only to the fascia boards but also to framing members.
You can see that the fascia on the photo appears to be in good shape. But hiding behind the trim work was trouble. Water had been penetrating the aluminum for a long time without anyone knowing!
Damage was isolated to the rafter tails. If it had gone on any longer the rafters would have had to be removed and replaced! In this case I was able to cut out the damage and replace the rafter tails.
I love the look of real wood! The fascia in this case if it had been painted pine, the damage to the fascia board may have been noticed prior to the extensive damage to the framing.