But "socialism" is a scary word

I think "it's human nature" is an excuse made by the ruling class to quell challenges to the system that benefits them.

Sociopathic hoarding and anti-social manipulation is an abberation that our system artificially elevates and rewards.

If we were culturally more hostile to attempts to rent out our lives and natural resources back to us, and didn't put zero-empathy profit hoarders on the front of magazines, things could be better.

I agree with you on group sizes though. When people are treated like hyper-specialized insects with ID numbers instead of identities, funneled into highly-specialized roles, every one a stranger to the other, something has gone horribly wrong.

I do agree that human nature is a huge problem. For a utopian government, I do think that is fairly impossible at the moment. As you have said we will need some novel idea or technology, or human nature will have to evolve in some way (that could take a very long time though).

As for citizens advocating for themselves, you seem to be thinking of peaceful ways to have a government that avoids becoming corrupt. While ideal, as we know humans are far from that and why eventually corruption turns to revolt if the needs of citizens are not met. I am not saying this will solve the issue either. As far as I can tell it just renews the cycle at best, or continues the corruption under a new group at worst. I only say this as technically this is a way citizens will eventually advocate for their rights if the government becomes too corrupt.

As for the desires of laws for each individual citizen, this is essentially impossible as only very small groups will have ideals and values that are homogeneous. In a populace large enough, human nature will lead to conflicting ideas on which laws should exist and how governments should run. In democracies, this plays into the hands of people or organizations with nefarious political goals. These groups can exploit human nature to get citizens to focus emotionally on a small subset of policies and laws. This tactic can be very powerful in places that don't regulate this kind of propaganda, such as the United States.

I would argue this form of political propaganda being pushed by powerful groups that don't represent the majority of citizens, towards citizens in other groups is one of the main cause of citizens being politically inactive. This creates biases and causes a lot of people to make decisions based on issues whose prevalence is artificially amplified. While that issue may be very important and should be advocated for, this should not be left to powerful groups or organizations that are not representative of the citizens. This also creates a ton of noise, making other issues that may directly affect or be advocated for by a large portion of the population to be obscured. All of this leads to information overload, fatigue, and complacency which leads to ignoring politics and possibly being politically inactive. I say possibly because people will still vote because it's their civic duty but will be uninformed which can be even more dangerous than not participating in politics. This also turns politics into a sport based on what the current political "hot topic" is, which a lot of people don't want to participate in and turns them away from being active politically.

In my opinion, the best solution to get citizens politically active is the need to make politics less biased and present legislation and policies in a fairer fashion. This will not get every citizen involved, but it will encourage more unbiased and informed decisions which will further fight corruption. Politically active citizens can look at legislation and policy proposals and make the sometimes difficult decision of which is the best choice in the present moment. This should also help with "political fatigue" which can cause citizens to not participate. Of course some people will never vote (unless forced to by law), but the best we can do is try to make the process simpler and use less of peoples time and resources.

All this being said, it will still be an uphill battle for democracies such as the United States to undo the influence of powerful groups in politics, and make their democracies fairer and more representative of the people. I wouldn't say it's impossible, but to do so peacefully will take a ton of perseverance, hard work, and most likely a bit of luck.