Playing a bit of devil's advocate here, it's likely a breakup will open the door for companies like TikTok, which are Chinese and outside of the US's regulatory powers, to fill the power vacuum. Then what?
I still think anti-trust measures make sense, but you also have to be careful what you wish for, how it's done and the potential fallout. I believe Zuckerberger will actually make that point to Congress these days (don't like him or FB, and like I said, I think they should be broken up).