I'm in the space industry and I can tell you that anyone pretending to be an authority on orbital mechanics on the internet is full of shit. I've taken entire classes called "advanced orbital mechanics." That shit is wildly hard, vaguely inaccurate, and so slow that you can only do it effectively on a computer. Even then you have to decide which variables to throw out because you if you use them all you won't be able to calculate predictions on every satellite in time for them to be useful. Then you have to take the predictions, predict how wrong they are, and predict again based on those predictions if two satellites will run into each other.

The truth is that nobody knows if Kessler Syndrome is even real. I personally fall on the side of thinking it's nonsense, there are too many variables that would have to go wrong all at once. It's like being worried about winning the lottery. There have been multiple catastrophic on orbit conjunctions that have created thousands of pieces of debris. Still no Kessler Syndrome. Even in a nightmare scenario I can only see it affecting one orbital regime. The odds of Starlink effecting the orbit that GPS is in is effectively not possible. But this is not a solved field and I am not remotely an expert, I'm just tired of people who don't know a thing about the field thinking they're experts because they have a JWST desktop wallpaper and have 300 hours in KSP. The real experts are ancient old men and women who have been doing orbital predictions for 40 years and I've seen them get into yelling matches about this sort of thing.

This post got away from me but the point is this shit is so involved it effectively can't be fact checked because you could come to whatever conclusion you want.