What about the fatgue of cfrp compared with metals?

CFRP has a benign behavior in fatigue when compared with metals with fatigue strength around 80–90% of the static strength in tension, compared to below 50% of steel. As noted by other answers CFRP doesn't has a fatigue limit, however its fatigue strength for a given number of cycles and loading is a lot better than any metal more so if you normalize by the materials density.

For instance, helicopter blades made from aluminum have a finite life of 6000 hours for example, where when those were replaced by CFRP ones, they considered to have infinite life, or at least greater life than the airframe itself.

So we have a lot of UAV parts made by composite, specially carbon fiber.