Allan Hirt is quite happy with contained Availability Groups:
All SQL Server availability features except Always On Failover Cluster Instances (FCIs) have a “problem”: when a secondary replica/warm standby/mirror (the term is different for each feature …) takes over as the new boss, some items such as SQL Server Agent jobs, instance level logins, etc., are not there. Going back to the early days of SQL Server when log shipping was not even in the product, this was always a manual process. There are multiple ways to approach this challenge and I am not going to detail them. This “problem” is a longstanding pain point with those who are responsible for managing SQL Server.
Contained AGs solve this issue by having their own master and msdb databases synchronized as part of the AG mechanism.
Click through to see how.