Chat backups are end-to-end encrypted now. You're right that it wasn't encrypted for a long time though.

I'm not claiming it's the ideal solution. I'm claiming it's much better than lots of other things that came before. There's no point in having a perfect solution if the people I know don't use it. Everyone I know uses WhatsApp. It's a fact that life could be much worse than it is. They could be using SMS.