At least they are finding nothing and confirming they are finding nothing. Less scrupulous operators might be always finding something even if its not there. So that's a sign of good science. Maybe there's something they haven't found because there's so much data? Mix things up and look again? Change assumptions? Or as someone I know likes to say to various smaller humans: have you looked around the couch? Really? Ar…
They've looked, been able to rule out some hypotheses of what they might find, and have established some evidence against others. Progress achieved, and the search continues.