Transfer of WhatsApp data is now available thanks to the developers working on the app. This was feature was launched along side the Galaxy Fold 3 and the Galaxy Z Flip 3 with other Samsung devices on their unpacked event on 13 August, 2021. This feature to work however you need a USB-C to lightning cable.
How it works
Transferring chats will only be possible if and only if both the iOS and Android devices are physically connected via USB-C to Lightning cable.
By any chance you have more than one cloud backup of your chat history and multimedia files and other backups won’t be merged. What will happen is. The transferred data will overwrite the existing backup once a new backup is successfully completed.
You won’t be able to transfer across platforms over the internet. This feature however is not clear when it is coming to other android devices. We have been assured that’s it’s coming but we are not certain of the time frame.