you will notice a WhatsApp section where it says “Messages: Limited*”, referring to unencrypted iCloud backups giving away messages which is no mystery. This is not an Android problem, and even better if chats are locally backed up on Android.
WhatsApp message content for one-to-one chats has not been compromised to date as far as E2EE goes, whereas metadata is unencrypted. WhatsApp messages atleast on Android can only be accessed in two ways — either user reports the other user to end up sharing the last few contextual messages between both parties, or by (forcefully) opening the phone. There is a third way, Israel/USA tools like Pegasus malware and Cellebrite toolkits, but those are reserved for high profile targets like activists and politicians.