I tend to agree in the here and now on carbon fiber. It is the wave of the future though. There are some great applications now but the field is wide open and the matrix possibilities are endless. There are chemistry departments at many major universities coming up with new ways to make it stronger.
http://compositesmanufacturingmagazine.com/2016/10/spacex-plans-travel-mars-carbon-fiber-spaceship/
CF is already being used for an increasing number of body panels on cars, but it’s not suitable for a truck bed and is unlikely to be so for quite a while unless something new comes out. The strength isn’t the problem, the problem is what it does when it gets punctured or cracks.