Yes, of course they have complained to the courts. That’s not the point.

That is moving the goalposts. In your other comment, you said, "What is the FTC going to do about it? Most likely do nothing, or issue a stern warning." I have demonstrated that they are doing neither of these things but instead are going through the courts to get injunctive relief.

This simply will go nowhere, or do you expect that the court will somehow separate Activision out of Microsofts hands again to fix this?

If the appellate court decides that the lower court erred in its reasoning, then there is no reason why it could not issue such an order. It is not like this would be the first time that the government broke up a company.

Or punish the managers at Microsoft and make them withdraw the execution plan to remove redundant jobs?

There is no reason why the court could not issue an injunction preventing it from executing this plan until the proceeding concludes.

At the end of it, Microsoft will eventually pay a small, symbolic sum which they consider “cost of conducting business”. Nothing more.

If the FTC considered this to be a sufficient remedy then they probably would have settled with Microsoft by now rather than taking this to the courts.