Privacy cannot come from human-made laws and regulations because they get abused on they change. Privacy comes from mathematics which do not care for laws and regulations.
You also do not have to backup keys in the cloud, however for most users it’s the best solution since for them data recovery in case of a hardware failure is more important than resiliency against state level adversaries.
Certainly, nation state actors could pursue those people to obtain access to key material, but that is a different hill to climb than simply sending requests to Apple, especially for contacts outside of the jurisdiction or nation state reach. Perhaps Shamir's secret sharing would be a component of such an option (you need X out of Y trusted contacts to recover, 2 out of 3 for easy mode, 3 out of 5 for hard mode).
With MSFT cloud backup of keys is an opt-in. With Apple it’s an opt-out.
For email each individual message should be encrypted if you want any confidentiality and even then the meta data is in the clear.
And this is because in order to send or receive an email the provider needs to access it. If they put it into a box later on to which they do not hold the key that is just security theater at that point.
A lot has changed since then and it is common knowledge that Apple regularly give government agencies access to their systems and hides it from the public until a whistleblower leaks it.
https://www.reuters.com/technology/cybersecurity/governments...
In a statement, Apple said that Wyden's letter gave them the opening they needed to share more details with the public about how governments monitored push notifications. "In this case, the federal government prohibited us from sharing any information," the company said in a statement. "Now that this method has become public we are updating our transparency reporting to detail these kinds of requests."