What is the point of GraphBuilder.QueueTextureExtraction()/QueueBufferExtraction?

Graphics novice here, so if you can identify any misunderstandings I have, correct me!

Currently wondering if GraphBuilder.QueueTextureExtraction() is necessary. From what I can tell it is effectively just a command list instruction (maybe??) that copies contents from an FRDGTextureRef (in my case, an OutputTexture buffer from a compute shader) to a TRefCountPtr<IPooledRenderTarget>, from which the texture can then be copied into a render-target of choice with RHICmdList.CopyToResolveTarget().

The thing is, RHICmdList.CopyToResolveTarget() takes an FRHITexture as both it’s source and it’s destination.

FRDGTextureRef has a function GetRHI() which returns a FRHITexture, so why ever call GraphBuilder.QueueTextureExtraction()? Just call RHICmdList.CopyToResolve() with FRDGTextureRef->GetRHI() as the source to copy from.

My guess is that it has something to do with the lifetimes of these objects. Maybe the contents of an FRDGTextureRef ceases to exist after you call GraphBuilder.Execute()?