Realistically I don't see forced break-ups being in the cards here. That hasn't happened since, what, AT&T, decades ago? My guess would be it's all consent decrees -- what they hit Microsoft with, and what they could hit Apple/Google/Facebook/Amazon/Microsoft with now.
Dunno about the US, but in Europe several companies in the last few decades have been forced to divest some part of their operations because of antitrust activity, typically (but not limited to) at merger time. Banks and telecom providers, for example, have seen quite a bit of movement in the Uk. It’s just that they don’t make massive headlines.
Apple is not in a situation where they need to be broken up to ensure a free market like Facebook, Amazon, and perhaps Google are.