They still are. The lower orbit only means that the satellites themselves deorbit within a few decades at most. Debris from a collision, however, goes every wh

They still are. The lower orbit only means that the satellites themselves deorbit within a few decades at most. Debris from a collision, however, goes every which way including higher orbits and can still damage other spacecraft. The satellites in geostationary orbits will stay up there for millions of years, but there's much more room between them and there's orders of magnitude fewer of them.