True. But if you share enough images from the same chip, eventually the fixed pattern noise can be computed to a decent enough accuracy to use it as a fingerprint. Now, you could measure the fixed pattern noise and subtract it from subsequent images. This is a widespread practice in scientific imaging. I'm not devious enough to think of how this could be defeated by someone who really wants to use your camera chip as a fingerprint, but it might be enough to defeat an amateur.

Dark-Signal Non Uniformity (DSNU):

https://harvestimaging.com/blog/?p=814

So likely to provide a few bits of entropy.