I really don't understand why Signal doesn't just keep a encrypted backup in Google Drive/iCloud. This seems like such a solved problem and yet they instead invented their own Bluetooth sync thing for iOS and manually copying files around for Android.

I'm hoping it will get there eventually. The backup mechanism on Android has improved a fair bit from what it was at the start. It used to be that you had to have the backup file in the correct magic path before starting Signal for the first time. Now at least there is a dialog and you can pick the file whenever.

The usability issues for non-tech people have been getting less and less in the past years which is keeping my hopes up.

Agreed. I understand they are reticent to allow backups for security reasons - but they're treating their users like idiots by doing this. Some people will have threat models where the ability to retain/export messages is worth the risk this may introduce. Let people make their own decisions.

Convenience vs Security - Pretty much any change made at the behest of convenience is at the expense of security. Honestly, once every 2 years having to move some files around...well, if that's the barrier that people aren't willing to push past, then we're pretty much screwed from the start.

You can't go from iOS to android with WhatsApp without paid applications... definitely not friendly