Steel, aluminum, carbon feeebray frames can and do last decades...even without much care.
I'm always working on 30-40-+ year old steel bikes, most of dubious ancestry, and with few exceptions they are all perfectly rideable...generally needing some care but the frames are all still generally fine, even where there are visible rusty areas. I'd not trust them on a 40+ mph descent or a 30mph hard corner but to plug along they are still fine.
Bike frames are more robust than most think. Can they fail? Sure can but generally it is a manufacturing problem isolated to a batch or a bike or few...I remember back in the late 80's a team I was close to scored a batch of Bianchi steel frames, through the supporting bike shop. They were beautiful frames and rode very well...until...apparently a manufacturing/welding defect occurred where the seat stay weld broke away from the seat tube. Bianchi took them all back, broken or not, and replaced them with new frames which never had a problem.
I don't think a carbon feebray frame has a built in failure point nor are they any more susceptible to failure than any other frame for generally all the same reasons.