Imagine for a minute the amount of good that could happen if all this money and research, public and private, were poured into the Earth and addressing climate change, pollution of the oceans, getting water and sanitation all around the African continent, fighting drought, replenishing the reefs, etc.
The Earth could be a wonderful place again.
There is way too much to be done here on Earth, for countless generations to follow, rather than focusing on fantasies in Space travel.