New Data Exposed episode: It’s just SQL: Restoring a database to Azure SQL DB from backup

This is all true, unless you have a large database. A BACPAC file is not a true backup, it is a compressed script consisting of a series of commands to recreate your database's structure, and then populate it by inserting the data into each table (in an order optimized to avoid foreign key issues) one row at a time. There are two possible performance issues with this. One is that is can be very slow due to the row by row nature of the inserts. The other is that behind the scenes, Azure uses a VM to process the import. https://docs.microsoft.com/en-us/azure/sql-database/azure-sql-database-hangs-importing-exporting#what-causes-the-process-to-take-a-long-time describes a possible performance problem related to that.

We have run into cases where the restore fails entirely because the special Compute VM Azure uses doesn't have sufficient capacity.