It is valuable and worth doing, just not as valuable, or as worth doing as the unmanned sensor platforms and robotic probes to other planets. The ISS does valuable work, I am very unconvinced that redoing the lunar missions is of much value though.
Even if space exploration turns out to be a viable solution for the survival of mankind as a whole, it isn't going to be a solution for the vast majority of mankind as individuals. We'll never be able to economically lift more than a tiny percentage of the world's population off the planet.I have heard the tired argument that we can use that money to fix things on Earth for my entire life. The western economies have massively spent more money.
Things have gotten worse.
We absolutely should spent money on manned space flight.
There are enormous resources in space and the key to clean energy. Factories and data centers can be moved.
We can build O’Neal type colonies at the Lagrange points to have full gravity.
Manned space travel and colonization is key to building a post scarcity future.
Spending that money here will never fix things. The planet has finite resources and room and it is clear that the massive amounts of social spending has not moved the needle at all.
The two are not mutually exclusive and I would argue that things like off planet manufacturing and resource acquisition can assist with putting things right here.Even if space exploration turns out to be a viable solution for the survival of mankind as a whole, it isn't going to be a solution for the vast majority of mankind as individuals. We'll never be able to economically lift more than a tiny percentage of the world's population off the planet.
So for the sake of the vast majority of people who are and will forever be stuck here it's a good idea to actually try to fix things rather than writing off the entire planet.
What you’re not considering is that expansion into space isn’t primarily about moving people off Earth. It’s about expanding resources and opportunities available to human civilization, and those benefits rebound back to Earth.Even if space exploration turns out to be a viable solution for the survival of mankind as a whole, it isn't going to be a solution for the vast majority of mankind as individuals. We'll never be able to economically lift more than a tiny percentage of the world's population off the planet.
So for the sake of the vast majority of people who are and will forever be stuck here it's a good idea to actually try to fix things rather than writing off the entire planet.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.