I agree it would likely take many years for #Signal to drop the phone number, although they could easily drop the marketing that subtly implies they';ve done this.
From what I've heard, #SimpleXchat sounds interesting. I'm just waiting for them to clarify what their funding plan is to pay back the VC's and fund future development. RIght now they have money and look like they're doing things right. Avoiding enshitification when the money runs out is hard though (*cough* Wire *cough*).