Interesting story. The never-ending dilemma of human survival. How will we destroy our planet, where will we go after that, and who will continue our legacy?
Would the world be better off without us?
Judging by the repeated mistakes even in our own time (let alone those made in times so remote we have little to no record of those), I don't think any attempt to rebuild will go very well.
To begin with, most likely the ones to survive will be the powerful, that is the one most likely responsible for whatever mess we end up creating.
WWI was supposed to be the war to end all wars, it just became the beginning of the technologically advanced slaughter machines.
By now we should have the resources and knowledge to stop poluting and share our territories peacefully, and yet everything indicates that many more wars will come.