> I heard StarLink satellites eventually re-enter the atmosphere when they are not orbit-stable. Thus this technology is bad for life on earth when it is lauched into space and again when decommissioned.

The fact that they re-enter by itself is not the problem. The problem is that they contain aluminium:

> When Starlink’s satellites reach the end of their lives, they burn up in the Earth’s atmosphere and leave behind small particles of aluminum oxide. These travel down into the ozone layer, which absorbs harmful ultraviolet radiation. Researchers from the University of Southern California found that these oxides have increased eightfold from 2016 to 2022.