gotta keep it pristine for those lower organisms who will have a better shot at utopia than we ever could.

But seriously, I always see the planet as on a finite timescale anyways with the lifetime of our sun being the limiting factor (which is interesting because it's the sun that gives us all our energy for the most part ignoring nuclear). Once the sun goes kaput that's it, we better be intergalactic by then. So I wonder can we think of perhaps maximizing the number of civilizational hours spent under the sun on Earth. Is that a good framework to go by. Put another way say the sun goes out in the year 10,000, and we are to judge two scenarios

A) humans go extinct in the year 7,500 B) humans go extinct in the year 9,000

All else being equal what scenario would people prefer and why.