There's no evidence of Meta actually fudging numbers in their history. Theres a huge lens applied to these numbers. Engagement is their bread and butter and what pays for everything else.
Facebook admitted in court it lied about its video advertising numbers.
It's not manipulating numbers, it's abusing their market position to push another product. Or at least that's what we called it when Microsoft did these things in the 90s. Now it's just how business is done