In the ten years of being a Bike mechanic I have seen more alloy cranks fail than carbon and no catastrophic carbon crank failures this of coarse may be due to the popularity of alloy cranks.
Two of the three bikes I own have carbon cranks this is because of my preference for sram xo and xx having said that shimano make lovely alloy cranks and I would be happy to ride them.
just ride what’s on the bike you want and remove the tin foil off your head.
