For all its flaws in Facebook integration, WhatApp is the single most impactful system ever in getting people to use secure communication. 1B+ people started using end-to-end encrypted communications overnight when WhatsApp enabled e2ee. This move pushed the entire industry towards adoption of e2ee.
Yes, they sold to Facebook. Yes, Facebook is doing everything it can to get the contents of WhatsApp communications so they can monetize. But it is impossible to not see the change they made on the landscape of communication privacy.
From my perspective, it's also remarkable that WhatsApp managed to enable e2e while already being owned by facebook. It probably won't last, but to me that demonstrates a commitment to security and privacy on the part of the WhatsApp team.
Yes, they sold to Facebook. Yes, Facebook is doing everything it can to get the contents of WhatsApp communications so they can monetize. But it is impossible to not see the change they made on the landscape of communication privacy.