There are multiple use cases for Equipment classes.
Grounded/Ungrounded Classes
This would allow clearance reporting to easily identify different clearance requirements based on the status of the equipment's grounding.
Communication/Utility Communication
This would allow breaking up communication equipment into different classifications as can be done with wires. Currently, this has to be handled using Owner Inclusion/Exclusion. Basing it on Owner is fine for a single client file, but makes it difficult to have a standardized approach to clearance case building across many different client files.