In the context of a messaging system anything other than E2EE is pretty worthless as far as I'm concerned.

To each their own. I've made a choice that I'd rather take the risk of leaking data to Telegram (real but I've reason to belive kow risk) than leaking metadata to Facebook (a given).

I'm considering Signal though.

But don't lie and say not not encrypted when you mean not end-to-end-encrypted.