People keep saying Google reads your emails (even when Google explicitly says otherwise), but have no proof, and trust Apple's words as the gospel of truth - ho

People keep saying Google reads your emails (even when Google explicitly says otherwise), but have no proof, and trust Apple's words as the gospel of truth - how strange. It's almost as if it's fashionable to criticize them. This is on Gmail's homepage: "We never use your Gmail content for any ads purposes. Gmail uses industry-leading encryption for all messages you receive and send. We never use your Gmail content to personalize ads."