Both platforms cover the same needs, but day-to-day operations differ on three points that matter in a managed services contract.
Identity. On Azure the corporate directory is central. Access management is designed from Entra ID and propagates to subscriptions, which is an advantage when a Microsoft directory already exists, and a constraint when it has to be reconciled with a separate application identity.
Billing structure. How subscriptions and resource groups are split determines cost readability. A split done hastily at the start makes FinOps tracking hard later, and fixing it means moving resources.
Licensing. Windows Server and SQL Server environments carry a licensing dimension that Linux environments do not. It is often the first saving lever on an Azure bill, before sizing.