Full Disclosure, although I come from an Amazon Web Services shop, we utilize, configure and install many of Microsoft's SAAS applications such as email and teams.  The AWS Well-Architected Framework is engrained in me from all the certifications and AWS training I’ve completed. It demands redundancy and high availability when designing cloud solutions. Based on that I assumed that the mighty Microsoft Azure Cloud had Availability Zones ingrained in all its services. 

But, while recently working through a vendor outage, I was surprised to find out that is not the case. After doing a little research, I found that Gartner reported last year that a limited set of Microsoft services support the availability-zone model.   This again shows who the leading cloud provider is. The leader is Amazon Web Services.  Amazon has had availability zones everywhere by default from the beginning.  To Microsoft’s credit going forward they are correcting this and just this month they have committed to offering Azure Availability Zones in every country they operate in by the end of 2021.