I don't trust un-auditable client applications...
If you want to assure me your e2e is secure, there must be at least two clients implemented by different people, with at least one of them opensource.
Whatsapp used to have this, but lately they have cracked down on third party clients.
> Whatsapp used to have this, but lately they have cracked down on third party clients.
Blame spammers on that. The amount of scammers and spammers on Whatsapp is unreal.
Even if they have, this doesn't prevent from turning on a feature flag, or push an experimental build to some users.