What of these companies has not been forced to split up by the federal government?

As of my last knowledge update in October 2023, companies like Microsoft, Amazon, and google have faced scrutiny and regulatory challenges but have not been forced to split up by the federal government. In contrast, companies such as AT&T and Standard Oil were historically required to break up due to antitrust regulations. The landscape of antitrust enforcement continues to evolve, but no current major tech companies have been mandated to split.