No, our existing infrastructure has existed longer than Azure existed. Azure is pretty new in town, I doubt there was much infrastructure built on it. So I believe people really wanted to re-build their infra out from AWS or GCP into Azure in the first place.
Basically my point is -- why rebuilding existing GCP/AWS infra into Azure in the first place? More so if it wasn't on any "cloud" at all before.
Sorry, I mean there was a point at which someone decided "let's go Azure". And that point was when AWS/GCP were already well-established (and provided Windows VMs for a long time).
So the only reason I see why they still wanted to go with Azure is the love for Microsoft.
Basically my point is -- why rebuilding existing GCP/AWS infra into Azure in the first place? More so if it wasn't on any "cloud" at all before.