IANAL and certainly don't want to defend those laws, but I believe FOSTA/SESTA ban providers from operating services with the intent to promote or facilitate various crimes. In other words, the provider has to knowingly distribute the material. I'm pretty sure that Apple encrypting its photo backup service would not satisfy these criteria, but if it did and the only way to comply with those laws was enforced CSAM scanning, then many CSAM prosecutions based on it would probably be tossed out.