My answer as an interested layman but not an expert: Yes this is a huge concern, which is why attention is being paid to how these satellites will de-orbit. U

My answer as an interested layman but not an expert: Yes this is a huge concern, which is why attention is being paid to how these satellites will de-orbit. Up to maybe 10 years ago satellites were just put up there and at best would move out of the way a bit when they reached end of life, but most would just stay. Plus lots of things were just discarded from mission, or lost accidentally, creating more junk. All of this made space junk a big and growing concern... However, now everyone is very aware, so satellites have de-orbiting built in (and I think this might be a legal requirement now), orbits may be chosen with ease of de-orbiting in mind, more care is taken to letting junk accumulate, several companies are working on clearup mechanisms, etc. All this may mean that the worst-case scenario doesn't ever actually play out, and it's not that big a deal in the long run. We'll have to wait and see, but there will be a lot of money behind making this as little of an issue as possible so that the space industry can really take off.