You're wrong though about it having zero factual grounding. They collect data, like everyone else, this is a fact. They state that openly in their privacy policy, they even go so far as to define what they consider personal vs non-personal information. We also know that that Siri collects and transmits a bunch of this "non-personal" information to a 3rd party for analysis.

On their QuickType page they say "your conversation data is kept only on your device, so it’s always private." That's a lie because iMessage and your keyboard Dictionary are synced to iCloud which isn't your device. That doesn't mean that it's in Apples hands or they can access it but it's not a factually true statement either. They're also careful to say "conversation data" and not something more general like "anything you input into your keyboard".

I'm not suggesting Apple does anything more invasive than anyone, I'm just suggesting they don't do anything less based on what's observed.