As squirtdad said, the alignment is key. Since we are talking longevity, the issue is change. Stuff that is most likely to change is the resin, the fiber can last a long time. Alignment determines how the resin is loaded, the extreme example is a tube that is wound mostly in the 90, this actually does exist one fairly well known example is the ugly stick fishing rod, but it is very common on any tube designed mostly for durability. Some braid in 45/45 is pretty common, these structures will have the resin as a large part of the stiffness, of course one can use fiber in all kinds of directions to create optimal structures. In practice well designed carbon should outlast the user as far as fatigue is concerned on bikes. Particularly if the tubes are virtually not deflected in use. Think fishing rods, golf shafts, or arrows without good fiber alignment and you would have structures likely to fatigue, but they also last a long time.