As far as I can tell their market control is limited to just their devices which though still significant isn't enough for a breakup to make sense to me.
That's not too say nothing should be done to prevent abuse of the control they do have.
Walmart yeilds quite a bit of market control. I'm not sure on the specifics though but they are a powerful retail force that's wrapped around many lives in the U.S.
While I am sympathetic to the issue, I'm concerned about how we can achieve our goals within the limits of the legal framework. Should we break up Kelly services or Robert half staffing? Should we break up GitHub?