Space is big.

Space is unbelievably hostile to meat sacks.

Space is at the other end of a deep gravity well.

It looks like we had one shot at using a cheap source of energy to make the leap off planet.

And failed.

Well done mankind. You had one job ...

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Maybe, there will never be another period of laying down fossil fuel on earth now that fungi that can digest Lignin have appeared. Which means no future life on earth will have the benefit of easy access to very large quantities of energy to bootstrap a technological civilisation.
https://phys.org/news/2018-02-fungi-nutrients-world.html