> This story is obviously satire.

Is it though? What is it satirizing? Is it satirizing the idea of water and carbon based life? How does that tell any truth?

It's a good question, because I would say it's mostly not satire. It's kind of making fun of the perspective of thinking meat is unimpressive, but that's not exactly a view held by anyone except in the fiction of the story. I think toward the very very end tonally it veers close to a satirical vibe but it's hard to put a finger on what about it counts as satire strictly speaking.

I think basically the humor is how unimpressed they are with a Sagan-style sense of wonder at the cosmos that is implicitly treated as the human perspective, how bleak it would be if true. The aliens ridiculing that is funny, and the actual bleakness of it is funny too.