FTC lost to Microsoft because the overall case was bewildering. Per Wikipedia, the merger would have made Microsoft the third largest gaming company. Which makes it clear that it faces plenty of competition.
In theory, they could abuse their market position by not selling games for the PlayStation, but you can't sue someone because they might do something. In fact, scrutiny from the FTC and the UK CMA seemed to motivate statements by Microsoft that they would not limit their titles (particularly Call of Duty) to their platforms. These statements were cited by Judge Corley when he denied an injunction against the merger. So even in this case there may have been some benefit.
As for Amazon and Facebook, the cases are ongoing; the former is very recent.
In theory, they could abuse their market position by not selling games for the PlayStation, but you can't sue someone because they might do something. In fact, scrutiny from the FTC and the UK CMA seemed to motivate statements by Microsoft that they would not limit their titles (particularly Call of Duty) to their platforms. These statements were cited by Judge Corley when he denied an injunction against the merger. So even in this case there may have been some benefit.
As for Amazon and Facebook, the cases are ongoing; the former is very recent.