The smaller any given piece of debris is, the greater it's surface area:mass ratio is, and therefore the faster it deorbits due to drag. Project Kuiper and Sta

The smaller any given piece of debris is, the greater it's surface area:mass ratio is, and therefore the faster it deorbits due to drag. Project Kuiper and Starlink both put the very large, thousands-of-satellites constellations low enough that trash gets cleared quickly enough that even a set of multiple catastrophic collisions is very unlikely to threaten most of the network, and even if they all just blow up, the pieces will fall down shortly and clear the orbit for reuse. For Starlink, drag is actually so high that they are using the solar array as a sail for attitude control.