This is where Apple's implementation, where the info is split between them and a third party with neither of them able to read the traffic on their own is so smart. Especially since there are multiple counter-parties to Apple. It also negates the risk of an MITM attack. Yes of course they could collaborate with a counter-party to break the system, but it seems significantly less likely to happen, and if it was happening it would be significantly more likely to come to light.