If you repair them if and when needed, they can last a lifetime.
Just don't make a habit of running up onto rocks.
The few times I had to beach a boat for any length of time, (camping)
I would always rest the bow on a piece of wood and tie the bow line to a tree.
Much easier on the aluminum than rock, sand
or gravel.
A night of high winds will do some nasty work if your boat is shifting back and forth on rock.