Perhaps it would help to clarify things if I explained my concern. Specifically, I'm concerned about the adverse effects of overtraining.

If my power meter is consistently under reporting my level of effort, it means that I'm consistently overshooting the target. I am far from an expert in these matters, but my guess is that the cumulative effect of constantly overreaching will interfere with my body's ability to adapt. So, for example, if I'm doing a workout consisting of several intervals at 130% of my 200 W FTP, but I'm actually doing 340 watts instead of 260, I don't think that's necessarily reason to rejoice. More likely than not, I won't finish the workout. In fact, looking back at the last six months, there are a number of the tough workouts that I did not finish. There could be any number of reasons for that, including the possibility that I'm just a wuss, but I'm just sayin'.