The idea behind having an all powerful centralized government is that this, in turn, removes power from all individuals over all other individuals within the borders of that government's auspices. No longer can husbands beat their wives or children into submission. Animals can't be abused. Criminals can't run amok. Foreign invaders are kept at bay. Corporations and the rich can't accrue so much capital and wealth that no one else has any choice but to be their puppets. Monopolies can't be formed and anti-competitive conspiracies are nipped in the bud. Frauds like Bernie Madoff are exposed and shut down. Pimps are prevented from tyrannizing over their ho's, and drug dealers are prevented from tyrannizing over their helplessly addicted customers. Loan sharks can no longer do whatever it takes to get their money back. The mafia and all their ilk are put out of business.
Local baronies don't declare they have the right of first bedding for every maiden on her wedding night. Local bandit gangs can't steal their nearby peasant village's food every year. Civil wars don't have to be fought over every disputed border between every local clan or noble house.
All power is sucked away and into the grasp of the omnipotent central government. This is the first stage of the prevention of all abuses within your borders. The second stage is that this central government is also neutered of any ability to abuse individuals as well through a careful series of checks and balances. The army is made up of volunteers straight from the common people, who are sworn to defend the common people, not their leader. The press keeps an ever watchful eye on government abuse and reports it daily and directly to the people, so that the government must always live in fear of a revolt if they go too far. Careful laws and red lines are drawn over what a government agent can and cannot do, and endless lawyers and judges police these government agents if they ever cross those lines. Jury nullification can stop any unfair government prosecution of a truly innocent individual in its tracks, and there is no extra-judicial process whereby the government may harm any citizen of the state. If any official seems to not be properly doing their job, elections can throw them out on a yearly basis and put in new, more honest officials who will better hew to the people's general will. Term limits also limit the power any government official can have and forces them to surrender their advantageous position before it has the chance to consolidate into a more permanent form.
The people are sovereign in this situation, and the government must act in such a way that pleases the people and conforms to the people's sense of right and wrong. Just like in who wants to be a millionaire, the wisdom of the crowd is very good at arriving at fair and objective judgments concerning contesting claims between private, self-interested parties. It is extremely rare for the people as a whole to have it in for any particular individual, they don't know you so how could they possibly develop a grudge against you, so the odds of the state, guided by the people's hands, would suddenly come slamming down on a random innocent guy is virtually nil.
As a result, with a strong centralized government in place, individuals can no longer victimize each other, but simultaneously the government has no way to victimize anyone either. A paradise of liberty and security ensues.
Once this primary role of government is served, secondary issues like providing a safety net or building out infrastructure to improve the economy or becoming the vanguard to new scientific discoveries can also make use of the strong centralized government which finds within itself the power to accomplish anything the people wish for it to. Plenty of people debate whether the government would be good in this role or that, on this issue or that, concerning these peripheral goals of government, but the primary purpose of government has already been secured long ago. It has long since stopped the casual violence and suffering that plagued mankind for thousands of years up until centralized government became strong enough, efficient enough, and organized enough to put a stop to it.
Once all the arbitrary violence and destruction ended, people were free to develop their talents, build their wealth and try out new ideas without the fear of this bringing unwanted attention to themselves and being punished by whoever didn't like what they were seeing. The industrial revolution, all progress on Earth, was made possible only once strong but just centralized governments came into power. The greatest invention of mankind was centralized government. Things like the steam engine or the laser are invented quickly and effortlessly once their fundamental principles are well understood, but without the gear in the clockwork that is the agglomeration of all power to a central point which is then policed by the polity as a whole, the whole world sputtered along for tens of thousands of years achieving nothing but misery and ruin to each other. Like Hobbes said, life was nasty, brutish and short, before the Leviathan (a strong centralized government) came to be.
It used to be that most people owned their own land. Even as serfs who technically didn't own anything, they would inherit the right to farm the same plots of land that their ancestors had farmed for centuries, and it may as well have been their land for all intents and purposes. People were essentially self-employed, and therefore didn't have to answer to anyone else on how they should go about their job supporting themselves. If corporations suddenly are necessary to get a job, and getting a job is a necessity to support yourself, then corporations can tyrannize over individuals again with the power of life and death in their hands. This is giving too much power to the executives of these corporations, and the government needs to remember its role as the only power in the land. The guaranteed basic income restores the circumstances America had originally during the homestead act, where nobody had to answer to anyone because they could always just go west and found a farm of their own and support themselves at no one else's behest or beck and call. The role of government now is to give people a guaranteed basic income, so that they have the freedom they lost when they became wage slaves instead of freeholders like in the past. And if any other private organization becomes powerful enough to dictate things to other individuals, the government needs to take appropriate action to forestall that as well. Government is supposed to be ever vigilant in defense of people's life, liberty, and pursuit of happiness. That can't happen when the only way to get a job is to grovel before those who are hiring, which in turn means grovelling to college professors by parroting their opinions, however false, in order to get a good grade.
All power should be vested in the state, and no power should exist outside of the state. Parents do not have the right to abuse their children, nor can husbands keep their women in line. Bullies can not gang up on little kids in the playground. Give any individual even a tiny sphere of authority and you will quickly discover that he is an absolute tyrant and monster within that sphere. It's better when no one but the carefully overseen and regulated government has any power over others at all.