Given that you can assign a process to use a number of robots rather than a specific robot (ie uses 2 robots out of a possible 10, it could be any 2) Why would you set an asset for a specific robot. I can’t think of a scenario where this would be practical.
One of the typical example is for credentials, where the application can only have one the same user logged once. (example SAP).
To work together, the robots would need different set of credentials.
It can also be useful, in case you do not want all robot to access all assets for security reasons but are not willing to have several tenants. The is generally the case for BPO/Shared services organization which would have one robot assigned to one business service/client.