The style of antitrust cases currently desired isn’t really a risk for a company. When Standard Oil was broken up, Rockefeller increased his wealth. Same thing with MaBell.

If Google were to be broken up, large shareholders are likely to increase their wealth. Those ownership interests don’t just get destroyed upon divestment.

And then barring some extraordinary fine the likes of which we’ve never seen, any punitive fines for antitrust violations are unlikely to harm the stock price. Googles share prices actually increased when the EU issued the largest fine ever against the company for violating their antimonopoly laws (presumption being investors feared a far worse outcome so price rallied when decision was released despite the nominal fine).