It means that at this point, ground based detectors probably won't work due to the massive amount of background noise (activities from people, geological activi

It means that at this point, ground based detectors probably won't work due to the massive amount of background noise (activities from people, geological activity, etc). There are plans for detectors in space that would not suffer the same problems. There's little reason, almost none at all, to think they don't exist. The standard model clearly predicts they should exist, and non-direct evidence has been seen already.