Nothing has changed in the basic physics that makes space travel, beyond the minimal scale achieved in the 1960s, essentially impossible. On the contrary, advances in physics have shut off every theoretical loophole that might have permitted us to exceed the limit imposed by the speed of light. Nor has there been any reduction in the massive amount of energy needed to propel even a single person into space.
The world is facing challenges that threaten our very existence, from pandemics to climate catastrophe to nuclear war. We can’t rely on fantasies of escaping into outer space. Nor we can afford a system that delivers a huge proportion of our collective income to a handful of irresponsible adventurers.