I would assume that Google, Apple and Microsoft are more or less same low level of privacy, maybe Apple is top of the 3 but still way to low. All of them will give anything they got if requested by authorities, Apple just did use a case where they refuse to hack into an iPhone to make it a good PR "we are pro privacy" advertisement but any data and metadata they store unencrypted will be handed over without a question. Proton had to habd over data as well in a couple of cases but at least they try to fight a little and they had only a few data to hand over in the end. It's just a matter of threat model, if your life depend on the security and privacy of your emails, you should not use Proto or many other email providers, in fact you should not communicate over email at all.
If you’re fully bought into any of the big tech platforms, then Apple has by far the best default privacy & security. Of course there is much nuance & tradeoffs… but Google is literally EvilCorp when it comes to user data. At least Apple’s business model is mostly around selling hardware.