People were saying everything you have said in the 60s and 70s. It didn't happen and we're only a tiny bit closer to it in 60 years.
Humans have been in space for 60 years. During that time, an average of less than ten people per year have gone into space, 95% of them within a few hundred miles of the Earth's surface.
No one has been born in space. About 10,000 calories of food have been grown, all lettuce, all from Earth-based materials.
No one has lived permanently in space. Each person in space still requires hundreds of ground-based support professionals to support him or her.
Now you're talking about moving billions of humans into space - somehow.
Why don't you try to make an estimate of how much it would cost to set up a completely self-sustaining colony on Mars?
I spent considerable time doing this. It's pretty daunting because it turns out that every single industrial process on Earth depends on unlimited quantities of air, for free, and on huge quantities of water, really cheaply.
Still, I estimated that if the cost of rocketry fell by a factor of 100 - which has never happened so far - you could set up a Mars colony for somewhere between $1 and $100 quadrillion.
(In other words, this means chip fabs and spacesuit manufacturing and everything, done right on Mars. This basically means you need to re-create the Earth's chemical industry, except using completely different chemistry that doesn't require massive amounts of air and water.
And for what? So a few tens thousand people can live on a freezing cold, airless, dark, arid, lifeless, poisonous radioactive desert in domes for the rest of time? (Because even if we spent the centuries and incredibly sums of money it would take to terraform Mars, ambient temperatures outdoors would still average around -40º.
Why don't people flock to live in the Sahara desert, or Antarctica, which are better to live in every way, and far closer?
For a tiny fraction of that money, we could save the biosphere.
Please, please, don't give me the false statement that we have enough money for both. We aren't actually doing either, and those quadrillions of dollars aren't just lying around doing nothing.
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I don't expect to convince you out of your religious beliefs on this matter.
You seem young. I predict in 50 years, we'll be no closer to living in space, but our ecology will have collapsed, and humans will be fucked for the rest of time, and at least partly because people believed in castles in the air and magic rather than dealing with the existential problems facing all of mankind.
I'm glad I won't live to see it.
