Nope! What we should break is the fingers of the idiot users that foist this garbage onto the rest of us.
It's hardly Big Company's fault that one non-employee X of Big Company forces another non-employee Y of Big Company to use something. It's X who is instigating it.
Things are early. IMO we should just see what happens. Tech is changing fast enough that all of this concern could be moot in 10 years. And I say that as someone who thinks Facebook (and social media, in general) is a cancer on our species.
Things can change quickly, you're right, but if the long-term secular trend is towards market concentration, then merely putting one giant monopoly in the place of another doesn't provide the kind of "change" we need for market competition to spur innovation and serve society.
Microsoft had (has?) a monopoly on the desktop OS (the only OS that mattered back then), before it diversified.
Google had (has?) a monopoly on search before it diversified.
Amazon has a monopoly on e-commerce, and is just now starting to really diversify.
Apple is the only exception-- they aren't really a "software" company though.
Claiming that Facebook should be broken up but not other big-tech companies isn't taking this into account.