[talaketu]

"Who cares?" reminds me of the diagnostician's distinction between signs and symptoms. Vital signs of the health of the biosphere can be measured, just like your blood pressure can be measured regardless of whether you I should care about how you feel.

[TeMPOraL]

"Vital signs" are still only meaningful in terms of humans talking about how the body of a human (or an animal, or a living or life-like system) should function. Blood pressure just is - whether its measured value is "good" or "bad", that's up to our preferences for what it should be.

If you remove sapience from this situation, then blood pressure just is, period. One particular aspect of what is just one big chemical reaction, or [insert whatever is at the bottom of how reality works].

It is said that since god died, the meaning of life is what we make it to be. But if there's no one around capable of processing the concept of meaning, then life has no meaning at all.

[talaketu]

"Would a tree falling in the forest ..." never seemed much of a puzzle to me.

I don't agree with the proposition that life on Earth had no value until it gave rise to the evolution of Homo sapiens, or that it would have no value after our extinction.