Why did the Vikings come to North America? Seeking land and resources? But, they only found wood and grapes for wine. Not worth the risk of crossing the North Atlantic in open boats. Ships and nav were too primitive for the trade.
The Spanish after Columbus fared better. They found gold, silver, and jewels that made Spain the richest country in Europe for over 100 years.
Why will people go to outer space, the High Frontier? Same reasons: power, wealth, and freedom.
Any nation that controls the High Frontier has air, naval, and land superiority over all other nations on Earth. A rock hitting the ground at 7 Km/sec has enormous energy. Chicom leaders, mostly engineers, KNOW this.
In terms of wealth, the mineral resources of merely the near Earth asteroids dwarfs the gold of the Aztecs in relative value. Sure, you can mine on Earth, but someone, often hostile governments, controls those minerals.
In space, no one owns the asteroids. However, it is established international law that if you mine it, you own it. Otherwise, how can the USA own the rocks we returned from Luna?
In terms of freedom, imagine industry and commerce with no earthly laws, regs, or taxes. If you don’t like the neighbors, move your habitat to a new location.
When I think of space colonization, I think of O’Neill type rotating habitats. Using AI and robotics, we can use the enormous amounts of iron, aluminum, titanium, etc. available to build whatever we want.
AI, robotics, genetic engineering, etc. can fuel a lot of economic growth. But, physical resources, i.e., minerals, will always be needed.
Humans require air, water, food, artificial gravity a la rotating habitats, and protection from radiation. Meet those minimum requirements and we can go anywhere and exploit whatever resources we find.
I understand that such an option is not for everyone. But, humans have colonized every possible environmental niche from the tropics to the arctic...using stone tools.
No new technology is required to colonize the High Frontier. Chemical rockets and spaceplanes work just fine to get to low Earth orbit. After that, nuke thermal rockets, which we developed over 40 years ago, are adequate to get to Jupiter and beyond. For nuke thermal reaction mass, you can use the abundant water found in near Earth carbonaceous chondrite asteroids.
Ad astra!
Sounds good. However, even the most extreme places on planet Earth are nothing compared to space. Cold, no oxygen, radiation, very harsh environment for food production. Short term, long term it is the most extreme. This has to be overcome.