"CF can fail suddenly and catastrophically" tis only a minor technicality
So... speaking of that potential. A carbon tube with the same strength and the same dimensions of an aluminum counterpart would be something so light and thin, that you could easily push your foot on it and crush. The kicker is, Carbon will spring back and be difficult to easily view or detect since it has shape memory. An aluminum tube would be deformed and retain the dent, it will also fail in a less abrupt manner when over stressed.
Years ago CF was introduced in hang glider frames to reduce the weight of the aluminum tubes for frames and leading edges. A 79 pound airframe was 45 pounds which is a huge advantage in all aspects of performance since you could fly a smaller glider which gave an advantage to sink rate / climb and overall reynolds numbers. Higher Reynolds numbers indicate turbulent flow, which is crucial for efficient flight performance. The catch was when I returned a glider to the factory that produced it after test flying it I got a rather disturbing update. The glider had at some point been run over by a car and crushed the outer portion of the leading edges. When you run your hand down the tube during a pre-flight the damage was not detected because it went back to its original shape. So, yes CF is an amazing material, I also find a place for alloy as well.