So, here's my concern: if you don't want to use WhatsApp because it's owned and operated by Meta, that means you don't have a lot of confidence in that end-to-end encryption.
And if you don't have confidence in it when it's run by Meta, why should you have confidence in it when it's run by Signal Foundation?
I assume this is because even when conversations are end-to-end encrypted, there is data exhaust around the edges -- like the timing of conversations, or profile data.