It does not seem at all clear to me that any tech company could sustain routine fines of this scale and remain a going concern. By Swisher's numbers in this post, 3 more fines of this size would deplete Facebook's cash reserves. A $5B fine represents most of the valuation of Slack, and an integer multiple of Discord, or any of a number of other "unicorn" companies Facebook could have bought, rather than shoveling that cash, in effect, into a furnace.
It's also not clear what the underlying violations of the consent decree are. What this analysis loses sight of is that the deterrence question isn't simply about what it would take to stagger Facebook as a company, but rather what it would take to deter them from the particular violations they're charged with. If this is about lax controls over data exposed in Facebook's API (generalizing from the Cambridge Analytica scandal), what's our guess as to how much money Facebook made by allowing partners to do that, or how much money they saved by not building and managing better controls? It seems unlikely to be an amount denominated in billions.
A company can be a goliath with hundreds of billions in reserve, but if a group inside that company that generates just tens or hundreds of millions of dollars reliably generates 5 billion dollar fines, that group is getting "reorganized".