Kessler Syndrome isn't optimal, but it won't be the overly dramatic Earth prison we hear about in worst case scenario stories. PBS Space Time did a video on this recently...

"The (Slow) Crisis Of Space Junk": https://youtu.be/LkeTk-Fi_c8

It's also a lot less likely with ultra-LEO constellations like Starlink. Not only do the satellites naturally quickly deorbit after loss of control, they're low and cheap enough that if necessary SpaceX can easily suicide-burn them to avoid catastrophe should it come to that.

Kessler syndrome doesn't result in denying access to space.