No need to import or search for system nodes like you would in a generic drawing tool. The most common system nodes are readily available. You can configure nodes with attributes that no other site does. For example, you can configure a load balancer with the kind of algorithm it uses: round robin, least connections, etc. You can configure a database with the kind of replication it uses, kind of sharding, etc.
This tool also helps students reduce the guesswork in system design and think about all the options available to them. The holistic system design can be depicted in the diagram. This tool helps system architects quickly represent their ideas in a diagram.