SProbot highlights sites which contain subsites, enabling you to determine a way forward to move content into a more modern structure if necessary.
Why should this be reviewed?
Microsoft does not recommend using subsites in its modern information architecture documentation. Subsites are mostly bad because they result in overly complex navigation at different levels, and can also cause access confusion with overcomplicated permission configuration. If you're still using subsites, it's recommended that you consider moving content into a modern flat structure using hubs instead.
Subsites do not cause any immediate critical issues, but it is good to be aware of their existence for planning purposes.
How do you see sites which contain subsites?
In Reports > Reviews, choose the Sites with subsites review.
More guides
Use the Reviews tools to proactively identify and resolve issues which may affect storage and security on your tenant
Use the inactive workspaces review to identify sites and teams which are unused and could be archived or deleted.
Use the channel sites review to identify workspaces which have channel sites and involve additional complexity.
