I guess Earth has a 'backup' life just in case the surface dwellers are stupid enough to destroy themselves. ;)
Scientists Reveal a Massive Biosphere of Life Hidden Under Earth's Surface
Earth is teeming with an incredibly vast biosphere of subterranean lifeforms.

https://www.sciencealert.com/scientists-lift-lid-on-massive-biosphere-of-life-hidden-under-earth-s-surface