Windows Virtual Desktop uses Microsoft Azure to provide the infrastrucutre services ( Broker\Monitoring\Diagnostics\Web Access\Gateway) needed to host a Windows 10 Enterprise multi-session Operating System – which is completely optimized for the sake of Office 365 ProPlus services, such as Outlook, OneDrive Files on Demand (per-machine), Teams etc and supports the addition of High End GPU’s for Graphics Processing
In terms of labour needed for the IT management of the system , the only effort is the Machine images on top of Azure Infrastructure-As-a-Service (IaaS). The rest is all managed for you through the Azure service SLAs
Licenses Needed
To run Windows 10 multi-session ( You will need Office 365 Shared Activation to run O365 )
Microsoft 365 F1, E3, E5, A3, A5, Business
Windows 10 Enterprise E3, E5
Windows 10 Education A3, A5
Windows 10 VDA per user
To run Windows Server 2012 R2, 2016, 2019
Remote Desktop Services (RDS) Client Access License (CAL) with active Software Assurance (SA)
Profiles
FSLogix Profile Container can be leverage with Azure Files to Store users Settings. Most of their documents should be stored in Onedrive to keep costs down
Authentication
Existing Azure AD Tied with Office 365 can be leveraged for access \ security and permissions ( Conditional Access )
Network
Microsoft Provides a Tool you can check your current internet connection Latency to Azure
Costs
Using the Azure Calculator ( which has a minimum seat count of 100 ) you can get a rough cost of users e.g. for Medium workload and 1TB space = 900GBP/Month
You just need to then virtualise you OnPremise Apps and Servers to Azure and you have just gone full cloud