Kessler syndrome is definitely a problem. I've heard SpaceX claims to deal with it by putting their satellites in an orbit that requires periodic boosting to s

Kessler syndrome is definitely a problem. I've heard SpaceX claims to deal with it by putting their satellites in an orbit that requires periodic boosting to stay put -- if they don't, satellites decay and de-orbit after a few years. The plan is, I think, to regularly retire (de-orbit) and replace these satellites so they can continuously improve the design, and as a nice side-effect any collisions or otherwise misbehaving objects will at least stop being a problem after a known maximum span of time.