He had a strategy and it worked very well. But every strategy must be updated. It's basic BCG matrix stuff every MBA graduate knows by heart: sooner or later your star product becomes a cash cow and then a dog. To keep your company growing, you need to identify your next potential stars among question marks, boost them with cash from the cash cows, put competent managers in charge and remove those who get in the way.

Gates did this with Windows, Office, XBox among other things. Ballmer failed to do this this with Windows Phone. Nadella did it with Azure, but he needs to do it once again with AI. You can see that he's pushing hard with Copilots everywhere, what's missing is a manager that has a coherent vision of what AI at MS should look like. ScottGu is in charge of both Azure and AI at MS, but I don't know if he can deliver.