So the ones I would be worried about right now, are those which have failed, but not yet fallen. Those can strike something else in process of launch or controlled maneuver. The pieces flying off of such a collision go in every direction including outwards, thus jeopardising things on higher orbits. Then there starts to become a real chance of a cascading event which takes out virtually everything in orbit. I really hope that doesn't happen, the consequences are almost unthinkable but the chances of it increase obviously with every new wave of added Starlink satellites.