The ecosystems at hydrothermal vents are self-contained enough to survive indefinitely if we went away.

The ecosystems living deep inside rock (basically just a few bacteria over a huge volume - possibly as much as half of the Earth's biomass) again wouldn't notice for a while if we destroyed everything upstairs.

And note that neither of these units needs us, and the more stable one (rock-bacteria) is not very diverse.

We still lose.

Cheers,
Ben