Please check the document [1] where you can see that you can configure Cloud Identity or Google Workspace to use Azure AD.
If you are a Microsoft Office 365 or Azure customer, you might have connected your on-premises Active Directory to Azure AD. If all user accounts that potentially need access to Google Cloud are already being synchronized to Azure AD, you can reuse this integration by federating Cloud Identity with Azure AD, as the diagram shows in [2].
Finally, refer to document [3] where you can compare services between GCP, Azure, and AWS. If you look for Amazon Cognito, Identity Platform [4] is the one used in GCP