1) Bitcoin's security depends on a supermajority of the economy using their own full node. CSAM means every full node will be actively engaging in child porn distribution. Most people will never be willing to do that. Without people using their own nodes, Bitcoin becomes just a worse version of fiat (including, but not limited to, inflation, seizures, etc). Spam makes it harder to run a full node, so is a similar threat over a longer period of time.