[ItsTooMuch]

Tell that to the solar flare that randomly burns everything on it... Or the asteroid that crashes into it... Or the black hole that eats it... Or the aliens that invade it... Or the plague that kills everyone on it... Or the supervolcano that causes "nuclear" winter...

We could be doing our absolute best and still be surprised pikachus anyways. And there's no scifi remedy that will help us resolve these problems, we're not even K1, much less K2 - who's on Earth when it comes dies.

As the only known example of intelligent life in the observable universe, we should be doing everything we can to preserve ourselves. Having everyone on one planet is not a good idea if you're looking for survival on geological timescales (and/or have bad luck).