No one said anything about permanently

That’s exactly what Kessler Syndrome is though.

Because that’s not how gravity works anyway

This isn’t about gravity it’s about orbital altitude. Objects in HEO or Geostationary orbit can stay at those altitudes for hundreds to thousands of years which qualify as “permanently” for all intents and purposes.

The thing you yourself quoted says it could take years for it to reenter. So that’s years of too much debris in LEO to launch anything safely.

No, that just means they can stay up there for years, not that it automatically makes it unsafe to launch into orbit. This is like claiming a 50-car pileup in Des Moines makes it unsafe to drive in Los Angeles.

I have no idea where you got the notion that Kessler syndrome means something like nothing can ever be launched again

[From Kessler himself](https://www.nasa.gov/centers-and-facilities/white-sands/micrometeoroids-and-orbital-debris-mmod/#%3A~%3Atext=The+Kessler+Syndrome%2C(900+to+1%2C000+kilometers).

This cascade of collisions first came to NASAs attention in the 1970’s when derelict Delta rockets left in orbit began to explode creating shrapnel clouds. Kessler demonstrated that once the amount of debris in a particular orbit reaches critical mass, collision cascading begins even if no more objects are launched into the orbit. Once collisional cascading begins, the risk to satellites and spacecraft increases until the orbit is no longer usable.