A whistleblower is not required to determine that Meta, and all adtech companies, have been severely damaging not just to the US, but to all governments and societies where these platforms are used. They don't need to collude with any adversarial government for this to be true.
The same tools built to manipulate people into buying things, are used to manipulate them into thinking and acting in ways that could be beneficial to someone. Advertising and propaganda use the same tactics, after all. When these tools are accessible to anyone, including political adversaries, it would be naive to think that they're not being used for information warfare.
The Cambridge Analytica leak was just the tip of the iceberg. These companies and agencies are still operating at a global scale, and business is booming. Why adtech companies weren't heavily investigated and regulated after this became public is beyond me. These are matters of national security, which anyone sane would consider more important than any financial or practical value they might have.
Banning TikTok was a step in the right direction, but that's far from the only service that needs to be heavily regulated. And even that decision is flip-flopped and very controversial, so the idea of going beyond must be unthinkable. Yet not doing so will lead to the eventual downfall of the US, and the current western hegemony. The instability we're seeing now is just the beginning, and my only hope is that it doesn't escalate to a major global conflict.