![](https://feddit.de/pictrs/image/4670a6ad-c99f-4afd-b206-ff15da3ffe3b.png)
![](https://lemmy.world/pictrs/image/0943eca5-c4c2-4d65-acc2-7e220598f99e.png)
Signal uses the same E2E encryption as WhatsApp and is also not Open-Source. One could argue that not being owned by Meta makes it inherently more private, to which I would somewhat agree.
The most private Messaging-App would be some kind of federated Chat, like Jabber or Matrix, that you or a collection of family/friends can self-host.
Unfortunately, nobody uses those ¯\(ツ)/¯
There are dozens of us!