Sure he build the foundation, but he was not smart enough to lead the path forward. With him MSFT would have never reached top 3 most valuable companies - I would say it would be at 500-600b maybe at best.
Even with Azure and Office, he was too much into "bundle with Windows" type of guy. Similar to how he was saying that touchscreen would never work as businesses needed buttons to type. I think with Satya, they would have tried multi touch screen at least for sure.
By and large, Ballmer was not the very open minded person. And his attempt to buy Yahoo...Oof.