The coup at AWS was programmable infrastructure. It's building blocks that fit together in the way that software engineers know and love: APIs. Sure there's a sales bro for the pointy haired boss and a console for the IT technician, but the thing is the API. It's going to be used primarily at engineering-driven companies, where "holy shit this is cool" is actually a factor in the decision. Most of those will be startups that flare out, but some will grow up to be tech companies that run very large, very locked-in, very expensive workloads. But an IT manager's only real interest in AWS is trend-following.
Microsoft thrives in a different world. IT managers are dealing with lots of different vendors (MS, VMWare, Dell, local HVAC and security contractors) to run their Windows Server workloads. It's pretty attractive to instead just pay Microsoft. But the nature of the workloads will not change, at least in the short term. It's still about technicians clicking in GUI consoles. I'd wager that usage of the Azure APIs is almost zero. Every business with a traditional IT department will end up with an Azure account, and the Fortune 500 is no exception. But the size of those workloads will scale with the number of enterprise apps they're running (each one its own VM). That won't necessarily grow with those businesses. It may even decline, as shrink-wrapped software for Windows Server is displaced by SaaS companies running on AWS.