I mean, why did we go to Mars without any intention of colonizing it? The Moon?
Exploration is what humans do. If Alpha Centauri is only 5 years away, you can bet we're sending people there no matter what. Permanent colonization only becomes a priority in an existential event, and if we eventually achieve ~1.0C travel then that implies our tech is at a level we'd be colonizing Mars and a few moons long before we think about leaving the solar system.
Even getting to 0.9C is going to be very very hard for humanity.
Exploration is what humans do. If Alpha Centauri is only 5 years away, you can bet we're sending people there no matter what. Permanent colonization only becomes a priority in an existential event, and if we eventually achieve ~1.0C travel then that implies our tech is at a level we'd be colonizing Mars and a few moons long before we think about leaving the solar system.
Even getting to 0.9C is going to be very very hard for humanity.