I mean what is the point of obsessing about the security of the messages if you don't value the messages themselves?
Some people[1] clearly value message history far beyond the transfer point to chat itself, and making people choose between being spied upon and not having message history, I think many people will choose trusting that they won't lose their messages.
[1] Myself included. I check with Signal[2] every six months to see if they have a backup option, then switch back to WhatsApp when I see they don't. Phones die. My messages are more important than my phone.
[2] https://support.signal.org/hc/en-us/articles/360007059752-Ba...