telegram did something important by being the first mass market “private” messenger that people were aware of. it has outlived this usefulness by nearly five years now. even the things that replaced it at this point are getting run into the ground and require replacing.
signal has been eroding it’s trustworthiness, and all the stuff you said is why myself and most folks keep using it despite its downsides. in a perfect world more of us would be working to make xmpp a viable option for most people but as it stands it’s a touch too technical for the average person’s mom and dad, who are ultimately who you have to appeal to