The goal isn't "moving anywhere else". There has never been a serious proposal to move a large number of people to a different planet for a long period of time. The point of space travel isn't evacuation, it is improving life on earth. Space travel involves a series of extraordinarily difficult challenges that result in useful spinoff technologies. It is true that things like docking two ships in space doesn't improve anyone's life, but that requires quickly pulsing lasers that were later used for LASIK. Spacewalks might not be inspiring, but the insulation used in spacesuits has been used to develop space blankets which are undeniably useful. I don't think we will save the planet without space exploration because it has lead to things like solar panels, GPS, weather detection, improved ability to quantify climate change, improved water production, and other things. Space exploration is a positive venture, not because it allows humans to leave earth, but because it makes our lives better.

Space exploration isn't that expensive either. The most well funded space program in the world costs 20bil/yr, and the most it ever cost was 50bil/yr. For reference, this is a rounding error compared to defense. I agree that we have much more pressing issues, but those are a result of capitalism, not poor resource allocation. Currently and historically, socialist societies have understood the value of research and spinoff technologies and have invested into socialist technologies.

I agree that billionaire space programs accomplish next to nothing, though.