Why does I3C allow more than one Master on the I3C Bus? What can a Secondary Master do that the Main Master can’t?
The system designer decides whether their system needs more than one Master on the Bus. To provide that flexibility MIPI I3C allows this, but also does not require it. Master handoff is a well defined and controlled mechanism in I3C; if used, it can be relied on.
For most use cases, a Secondary Master is not a required component for an I3C Bus. If your Main Master has all the capabilities and features that you need, and if your use of the I3C Bus wouldn’t benefit from having multiple Master-capable Devices, then you might not need a Secondary Master.