This is a problem as well. As the satellites deorbit they vaporise, leaving aluminium oxide nanoparticles (and other metallic gases, volatiles etc) in the atmosphere, destroying ozone and building up over decades.
So it’s not just the light pollution, or the ruining of ground based astronomy. Or even the dangerous amount of clutter polluting LEO, making spaceflight even more risky. Starlink is bad news for the environment, but it’s to be expected since we’ve seen how carelessly spacex have destroyed the ecosystem in Texas.