You are incorrect. Orbits can't cause a Kessler Syndrome. Kessler Syndrome can occur at any altitude. But you are correct that the orbit places a bound for how long the Kessler Event can take place.
A bound in time is different from not possible. Do not confuse the two.
There's also 2 critical points:
1) The lower the altitude, the easier it is to create. You need less debris to fill the orbit.
2) Even a 3 years "lockout" period would have significant consequences on our world due to our reliance on space.
Also, remember that when objects collide that this can send parts into higher orbits, which will take longer to deorbit. Even just through collisions, while the total energy of the system may be lower than the input this does not require each object to have the same or less energy prior to collision. Then we also have to consider that some craft have propellants. Considering that Starlink satellites have collision avoidance systems on them, it is quite safe to assume they have propellants. This similarly can result in more objects ending up in higher orbits.
Remember, just because it sounds right doesn't mean it is. There are non-negligible factors at play here and overly simplistic models will lead you to the wrong conclusion.
(Source: I have a degree in physics and formerly worked in the space industry. My job consisted of modeling a lot of things, including radiation transport, orbital dynamics, and acoustic engine stability. I'm not stating this to flex, I'm stating this to claim I'm not just some rando who read a few wiki pages)
A bound in time is different from not possible. Do not confuse the two.
There's also 2 critical points:
1) The lower the altitude, the easier it is to create. You need less debris to fill the orbit.
2) Even a 3 years "lockout" period would have significant consequences on our world due to our reliance on space.
Also, remember that when objects collide that this can send parts into higher orbits, which will take longer to deorbit. Even just through collisions, while the total energy of the system may be lower than the input this does not require each object to have the same or less energy prior to collision. Then we also have to consider that some craft have propellants. Considering that Starlink satellites have collision avoidance systems on them, it is quite safe to assume they have propellants. This similarly can result in more objects ending up in higher orbits.
Remember, just because it sounds right doesn't mean it is. There are non-negligible factors at play here and overly simplistic models will lead you to the wrong conclusion.
(Source: I have a degree in physics and formerly worked in the space industry. My job consisted of modeling a lot of things, including radiation transport, orbital dynamics, and acoustic engine stability. I'm not stating this to flex, I'm stating this to claim I'm not just some rando who read a few wiki pages)