First, you never specified LEO, only “space”.

Second, the situation is already so bad that current satellites in LEO already require active collision avoidance systems in order to avoid becoming sources of debris themselves. Starlink alone reports over 1,600 close encounters each week.

> you never specified LEO, only “space”

What I said applies to space, too, outside GEO, for the number of satellites anyone is currently talking about launching.

> the situation is already so bad that current satellites in LEO already require active collision avoidance systems in order to avoid becoming sources of debris themselves

They require collision avoidance to avoid being lost. There is no risk of a Kessler cascade in LEO right now and nobody who can do orbital mechanics is claiming as much.

We’d need millions more satellites than we have right now to start approaching the point where atmospheric clearance falls below the rate of new-debris production. And even then, you’re talking about a problem in specific orbits for months, maybe years. In the meantime, you get to allow nature to reclaim huge amounts of land from cell towers and conduit.