Colonization in another system is a monumental effort. Interstellar supply lines would have to be maintained for decades before a colony can become fully independent. The opportunity cost cannot be understated. My opinion is that there's little reason for humanity to expand beyond the existing systems already under human control.
Resource Extraction: With existing space mining technology, it's cost prohibitive to maintain interstellar supply chains to harvest resources from another system when there's plenty of resources still untapped in the local systems.
Living Space: Perhaps this is the reason why the Groskande colonial project exists, since the CoW and the Soyuz lack comfortable living space compared to the other powers. But once a superstate has control over another habitable world, that's a massive garden that can support tens of billions of people with the right sustainable practices in place, especially when the human population won't reach that high anyways.
Strategic Depth: Maybe there's a fear of alien powers and there's a perceived need to put flesh and metal between them and the core human worlds. The problem here is three-fold. 1) There's very little evidence of aliens that can threaten human life, and those that can are already present in human systems. Which leads to 2) By the rules of current FTL travel there's nothing stopping a power from simply bypassing a frontier system to each the core systems. 3) If defensive depth needs to be created, it's better created around gravity anchors in the same system as population centers so that even if these defenses are bypassed, they can still project power and create problems for an invading force in an actionable time frame.
That last point really leads to the overarching, core issue: opportunity cost. Whatever the benefits of colonization are, they can be done cheapy, and to greater magnitude, in existing systems with existing infrastructure. All the cost associated with distance, all of the extra bureaucracy required to maintain long supply lines, these resources can be instead devoted to improving existing infrastructure and systems.
Resource Extraction: With existing space mining technology, it's cost prohibitive to maintain interstellar supply chains to harvest resources from another system when there's plenty of resources still untapped in the local systems.
Living Space: Perhaps this is the reason why the Groskande colonial project exists, since the CoW and the Soyuz lack comfortable living space compared to the other powers. But once a superstate has control over another habitable world, that's a massive garden that can support tens of billions of people with the right sustainable practices in place, especially when the human population won't reach that high anyways.
Strategic Depth: Maybe there's a fear of alien powers and there's a perceived need to put flesh and metal between them and the core human worlds. The problem here is three-fold. 1) There's very little evidence of aliens that can threaten human life, and those that can are already present in human systems. Which leads to 2) By the rules of current FTL travel there's nothing stopping a power from simply bypassing a frontier system to each the core systems. 3) If defensive depth needs to be created, it's better created around gravity anchors in the same system as population centers so that even if these defenses are bypassed, they can still project power and create problems for an invading force in an actionable time frame.
That last point really leads to the overarching, core issue: opportunity cost. Whatever the benefits of colonization are, they can be done cheapy, and to greater magnitude, in existing systems with existing infrastructure. All the cost associated with distance, all of the extra bureaucracy required to maintain long supply lines, these resources can be instead devoted to improving existing infrastructure and systems.