Assuming this is going on, should we expect to be able to detect these gravity waves somehow? They would be coming from all directions and we ought to notice them if they are 'bright' enough and perhaps even form images. Or are they so weak and smooth that we can't devise instruments sensitive enough to register them?
I think your question is probably on the mark: they are so weak we cannot measure them.
Heck, two black holes waltzing around once per minute 100 LY away we can't detect...
--Boris