Space is big. It's extremely unlikely to get close to any object while randomly passing through its orbit. Unfortunately, space becomes a lot smaller once you

Space is big. It's extremely unlikely to get close to any object while randomly passing through its orbit. Unfortunately, space becomes a lot smaller once you want to park yourself in a similar orbit to another object. Don't get me wrong, it's still massive, but since orbits trace out a path the problem becomes figuring out if two paths intercept rather than if two points intercept. This is why access to 'space' will not really be impacted in the case of a Kessler cascade; you can go through low earth orbits on the way to somewhere else, but if you tried to stay in low earth orbit you'd almost certainly be hit by something.