The encryption protects you against others snooping on your messages in transit which is what it is meant to do. Absolutely mothing really stops any of WhatsAp

The encryption protects you against others snooping on your messages in transit which is what it is meant to do. Absolutely mothing really stops any of WhatsApp, Apple or even Signal itself from reading your messages if they want to/are compelled to. The only way to protect yourself against the service provider is to manage public keys yourself manually using GPG like workflows which have proven to be unworkable. The trade off is do you want free and easy to use messaging which protects you from other snoopers but not the service provider/government itself or do you want much more secure systems that no one outside the technology priesthood will use.