> Our society is pretty aligned that distribution is another kind of harm.

As well as possession. I don't actually know if those are different for CSAM, but I would assume so because they are for drugs.

Meh, I assume "possession" (of drugs) is how the law is worded because otherwise law enforcement would have to catch someone in the act of using or distributing, which must be much harder to do.

Mere possession of a substance is surely not what society cares about.