They're absolutely not too big to fail. Equifax or FB? Other than the unfortunate employees and their families, does anyone give a shit? No. No one suffers. To the contrary, thinning sick herd members helpfully invigorates the health of the surviving individuals.
What these organization are are in too many pockets to be too big to jail. It's a trope but it's a fact, Jack
Edits for herd reference and reduced snark
And yeah, ditto Equifax. There are two other credit agencies already. They're all same-ish as far as I can tell. Pretty sure there are only three so they can pretend there's competition, not for any actual purpose. Again, it might be an opening for a new competitor anyway, while causing minimal short-term harm.