I have no idea what the right answer is, however "solving" implies that the states are "huge problem" and "no problem".

I might say that it's possible there are actions that can reduce, but not eliminate, the problem. What if another 20 million reports saved one child from exploitation? 10 children? 1000 children?

At some level, this boils down to a society question. We all agree CSAM is evil. How does it stack up against other things we think are evil? I fear that, in the end, there is no middle ground that includes eliminating CSAM and keeping 100% privacy.