I love these topics. While we might be nowhere near Kesssler Syndrome, the risks of space debris impacts are very real [2]. Some of the debris we've put up there intentionally and it's quite insane, most notably Project West Ford [3].
I believe that now anything put in space has to have a plan for how it will be decommissioned. For LEO probs, that typically means burning up in the atmosphere or, if it's large enough, crashing in Point Nemo [4]. For geostationary satellites, they're typically put in a disposal or graveyard orbit [5]. That doesn't solve the problem. It just kicks the can down the road.
People might think you can just accelerate a bit and leave Earth but that's not how orbital mechanics work. If you accelerate a bit you've just created a new orbit. You still need a lot of energy to leave Earth orbit. It's the same reason why dumping waste into the Sun (as some like to suggest) is completely unworkable. You can't just slow down a bit and fall slowly into the Sun. You just create a new orbit. It still takes a delta-V of ~30km/s to hit the Sun [6].
Fun fact: it requires less delta-V to reach Pluto then hit the Sun than it does to hit the Sun directly. Orbital mechanics are weird.
EDIT: fixed delta-V units.
[1]: https://www.youtube.com/watch?v=GCCKpI80V6M
[2]: https://www.space.com/9708-worst-space-debris-events-time.ht...
[3]: https://www.wired.com/2013/08/project-west-ford/
[4]: https://www.atlasobscura.com/articles/strange-maps-point-nem...