Explanation
SQL Managed Instance enables system administrators to spend less time on administrative tasks because the service either performs them for you or greatly simplifies those tasks.
Note: Azure SQL Managed Instance is designed for customers looking to migrate a large number of apps from an on-premises or IaaS, self-built, or ISV provided environment to a fully managed PaaS cloud environment, with as low a migration effort as possible. Using the fully automated Azure Data Migration Service, customers can lift and shift their existing SQL Server instance to SQL Managed Instance, which offers compatibility with SQL Server and complete isolation of customer instances with native VNet support. With Software Assurance, you can exchange your existing licenses for discounted rates on SQL Managed Instance using the Azure Hybrid Benefit for SQL Server. SQL Managed Instance is the best migration destination in the cloud for SQL Server instances that require high security and a rich programmability surface.
Reference:
https://docs.microsoft.com/en-us/azure/azure-sql/managed-instance/sql-managed-instance-paas-overview