Literally no "non-tech-savvy" person I know backs up anything at all. I seriously doubt that backup / transfer is on anyone's mind at all when deciding to use a new messenger.
I mean, for most competing apps this backup is completely transparent. It's when they reinstall Signal that they'll notice all their messages are gone irrevocably.
I don't understand this claim: I don't know any non-tech person who has WhatsApp backups enabled and working. If I don't go through the process with them when they're changing phones they'll literally start from blank state and are ok with that.