If the report is predicting 100 years in the future, are we really "to the brink" now? Not to mention the decay time of these LEO is in months, hardly a kessler syndrome scenario.
The report says we will be in trouble in 10-20 years, not 100. Look under "collisions causing collisions". Debris from previous collisions increases the risk of future collisions.
It probably doesn't matter. Global warming has proven that we are incapable of doing the necessary things to slow or stop the human-caused decaying of our planet. I'm starting to think we deserve what we're gonna get.