As I said, I agree with the literal facts. The implications in your phrasing I disagree with.

Instead of unfounded, I would call it unproven.
Instead of scaremongering I would say warning.
And generally I avoid using absolute terms like "all", since only it takes one counter example, to make such a statement factually wrong.

Facebook is literally arguing to the US federal government that regulations about social media usage by children, and the data they sell from it, aren't their problem but are the responsibility of Google and Apple.

Why do you trust them?