⇧But in what situations would you use the WhatsOnChain plug…

You can use the different indexers as fallback, so when one isn’t working you use another.
Sometimes the indexers get out of sync and don’t properly reference content.
I think @3dordi implemented an automatic fallback that iterates through the different indexers to help ensure content always shown.

That's right, I use Gorillapool as the main indexer, but if that indexer isn't available, @3dordi automatically checks Ordfs as a fallback, and if that's also unavailable, It download the content from the WoC plugin as third fallback.
I also have other secrets to increase the platform's availability to over 99.99%; [[3dordi]] has never experienced an outage or be offline for maintenance. The indexers fail before the app does.