SpaceX satellites are doing about 1000 collision avoidance maneuvers every single day. The addition of new networks is going to congest things even more and the risk of unavoidable cascading failure keeps increasing at a massive rate.
Genuine question: how many avoidance maneouvres does maritime traffic execute in the open ocean?
[1] There are counterexamples, like in narrow chokes & whatnot.
Space is big. Volume grows with radius in a way our intutiions don't seem to intuitively understand. Yes, debris in a space collision go further. But they're still bound by their energies. And that larger volume of collision debris (plus all other stuff in orbit minus the Moon) is still a smaller fraction of the orbital space than e.g. commercial air space on earth, and yes, that's including oceans.
You can remove curbs and any other barrier to simulate the fact that cars can maneuver away from a crash site, but if no site is ever cleaned, and no car has meaningful brakes, crash sites are much scarier.
Just one collision in space carries an ever-increasing risk of cascading into a major event with long-term effects (there's no a good way to call in a space wrecker to haul billions of tiny bits out of orbit).
This isn't how debris clouds work. The most-complex ones occur when entirely separate orbits collide were you get an X-shaped (versus cylndricla or conic) debris cloud. But the energies of the collision inputs sharply curtail the orbits and places in said orbits the debris fragments can generally reach.