MS has established business relationships with large corps to a much greater degree than Amazon. They're already entrenched as nobody's moving away from Windows desktops or Office anytime soon, so the upsell to cloud for them is trivial.
For developers it seems that Azure tends to settle at a clear #3 behind AWS/GCP for most. It only makes sense that Microsoft would look to carve out an enterprise niche. They seem to have done a decent job keeping their enterprise stuff fresh, I'm honestly surprised they didn't go the way of IBM/Oracle.