I am currently testing the premise that carbon frames have a limited life. My 1992 TVT was raced for 3 years, then ridden for training for another 15 years. Total of >35,000 km. Now it is on Kickr trainer for Zwift, and has done more than 500 hours (~16,000 km) including races and 900W sprints. People say that the old carbon frames will blow up under such "abuse" especially on a trainer, but to me this is what the frame was designed to do. My view is that if the frame is not crashed, it should last longer than you would want ever want to ride it, at least 50,000 km?