Just to be clear, Microsoft tried to buy Yahoo for $45 billion in 2008, long before Marissa Mayer was CEO.
As the parent comment notes, your previous comment seems to suggest some kind of causation between Mayer’s tenure as CEO and the eventual breakup and sale of Yahoo. This is the fallacy known in poker as “resulting”.
Nicholas Carlson’s “Marissa Mayer and the Fight to Save Yahoo” is a fair account of her first few years at Yahoo. Keep in mind that when she joined, there was something like a total dozen mobile engineers at Yahoo. The company had burned through 3 CEOs in a decade, etc.
Mayer was not a perfect CEO in terms of strategic vision or her choice of acquisition targets, but I don’t think her time as CEO was particularly bad either.
In ER terms, the surgeon could have cut the leg off and saved the person, but got a bit too greedy and ended up killing the person by trying to save everything.