The billionaires are looking at Mars, saying that Earth might fail to keep us alive eventually. They're not wrong, as rampaging climate change indicates.
But have a look at Mars. It's infinitely less habitable than the Earth will ever be. If we ever figure out how to survive in that environment then surviving in whatever hellscape we've turned Earth into will be child's play. And that renders the trip to Mars moot. There'll be no point in going.
Let's hope life remains bearable here, though.
-- CC0 Björn Wärmedal