Hello Tom
You have described a fundamental difference between how the the VSS, stackwise, and vPC solutions operate. Just one clarification. When you say “control panel” I assume you mean control plane, correct?
Indeed, VSS and stackwise are designed to merge multiple physical switches into one logical unit, but they operate with a single control plane. This means there is only one physical switch that is actively using its control plane, managing the entire stack or VSS system. This provides equipment-level redundancy. If the control plane fails, the whole stack or VSS system is affected. However, this does not mean that the whole logical switch has failed. The other switch or switches will take over control plane operations almost immediately, with little to no downtime.
vPC can also make multiple switches appear as a single logical unit, but with a crucial difference: each switch retains its own control plane. This independent control plane setup provides system-level redundancy because they both operate at the same time. This adds an additional aspect of redundancy. vPC is only available on Cisco Nexus switches, which are designed for data centers and other high-availability applications. This is why vPC offers a higher level of redundancy compared to VSS or Stackwise.
For more information about MLAG and terminology, take a look at this post as well:
I hope this has been helpful!
Laz