Yes, I agree launches also contribute and increase frequency is also a plausible risk factor (and is significant increases in launch frequency themselves driven

Yes, I agree launches also contribute and increase frequency is also a plausible risk factor (and is significant increases in launch frequency themselves driven by megaconstellations, though I don't think the Falcon 9 is as problematic as the Shuttle was) Main difference is that the satellites lose most of their mass in the relevant zone, whereas launches pass through it as quickly as possible. Satellites are small, but Starlink's deorbiting cycle is expected to reach 2 tonnes per day.