Microsoft's biggest failure was Windows Mobile. If they got Mobile right hands down they would be on a highway to $10T company but otherwise they are riding the wave of cloud, AI and gaming. Like Steve Jobs[0] said they are strong opportunists, they have no taste, they don't have original ideas and they don't bring much culture into their product but they keep on coming. Microsoft uses its big cash pile to either acquire companies or to copy them.
[0] https://www.youtube.com/watch?v=KSg3fU9XWow