You seem to be implying that E2E is impossible without client-side CSAM scanning, but this is obviously false since other companies offer E2E without that.
Not technically impossible, but legally risky, and Apple are very risk-averse, legally-speaking.
Client-side CSAM detection would allow full client-side secrecy unless there’s a pattern of in-violation imagery destined to be sent (presumably E2E encrypted and thus undetectable) to iCloud.
Client-side CSAM detection would allow full client-side secrecy unless there’s a pattern of in-violation imagery destined to be sent (presumably E2E encrypted and thus undetectable) to iCloud.