Navigation Invokers

In the above ss, do we have to add navigation invoker component to BP_NPC

Documentation Link - Using Navigation Invokers | Unreal Engine Documentation.

What would be a real world example someone would use this for?

For generating navigation mesh at runtime

Why, yes, I did understand that, but if you only have navmesh a few hundred or even a few thousand units away, how are you going to be able to actually path anywhere?

Again – what would you actually use this for, in a real life example?