WhatsApp's E2E may not be backdoored (maybe), but it is 100% backdoored for metadata and social graph (contacts, group membership, etc.)
Example of this :
https://scroll.in/article/1044425/how-a-cross-border-love-st...
An even more egregious example : https://news.ycombinator.com/item?id=39918245 Facebook-Meta and Whatsapp maybe accessories to warcrimes perpetrated on a massive scale.