Sure, issue is, if OP math checks out, currently everyone already voluntarily agrees to international law - ITU coordinating LEO orbits that extends to 2000km, meaning hard to clean >400km orbits is going to be filled with 100,000+ megaconstation hardware in next decades, substantially increasing chance of kessler. Op propose limiting >400km orbits... which means US is going to be unhappy sharing space with PRC megaconstellations. PRC not going to accept limiting >400km orbits without openning more <400km orbits because it means ceding advantage to US who locked in high% of <400km orbits since US grabbed megaconstellation spots earlier. So either everyone shares / free for alls <400km orbits, or everyone suffers Kessler, in which case whoever has the most space hardware might end up losing the most.