It's true that there is less GEO real estate in this sense. But to kick off Kessler syndrome, you need two objects in different orbital planes so that they coll

It's true that there is less GEO real estate in this sense. But to kick off Kessler syndrome, you need two objects in different orbital planes so that they collide at very high speed. It wouldn't be possible for two defunct GEO satellites to collide, because two nearby GEO satellites are moving in the same direction at the same speed.