A Kessler cloud would not persist in orbit at the altitude of Starlink satellites for very long. And building and maintaining a Kessler cloud at that altitude

A Kessler cloud would not persist in orbit at the altitude of Starlink satellites for very long. And building and maintaining a Kessler cloud at that altitude seems like it would be… not effective with just a handful of rockets due to the significant atmospheric drag. Kessler syndrome is a real concern, but only at higher altitudes where atmospheric drag is negligible.