It sounds anarchic, but if you were somehow to be able to flip between a failed state and actual anarchy at a whim you'd notice some important differences. In a failed state the government still has pretenses towards being a state, so they occasionally crack down and attempt to show they are still a state. This frequently actually fools many of the people living there. Consider birth control in the world of the Fixer. It's not actually hard to get, but I don't think any of the named female characters other than Sammy herself actually know that, they seem to simply assume that because it is illegal it is difficult to obtain. Meanwhile, prostitution is an ostensibly illegal activity which is harder for a failed state to throw their weight around to interfere with, because they can't disrupt the supply upstream. I suspect that guns in this setting would be about as hard to obtain as birth control, even if Sam_Tail thinks otherwise. Contrast that to how it would work in actual anarchy, if you wanted birth control, you could just pick it up from a store that would advertise openly, same with guns.
EDIT: The government in this setting doesn't have the capacity to be totalitarian, even if they aspire to it, they haven't even been demonstrated to be able to collect taxes. Sam_Tail has said there are two groups of guards in the city, one guarding the train station that is drawn from the remnants of the military, and the gate guards, who are drawn from the remnants of the police. Neither of them are very numerous, and they have their hands full just guarding the two ways into the city.
I agree, a government crackdown would make a difference, but that requires the state to have enough power in the region, or the interest, to do so. With larger issues at hand it could simply be left as an autonomous region, too much to handle presently and only dealt with if their chaos spilled out into other areas. This doesn't even require societal/governmental collapse. If you're familiar with 'The Wheel of Time' (the books, not the bastardized streaming show) there is a good example of this. Fiction, I know, but bear with me. In it, the Two Rivers region technically exists within the nation of Caemlyn. The crown claims it and expects its residents to acknowledge royal authority. Other nations recognize this. This is news to the population of Two Rivers, who have effectively been neglected by the national government for so many generations that they have no idea they fall under any authority but their own. They have their own government and laws that they apply themselves. It's only when residents leave the region that they find out the rest of the world has other ideas.
For a real world example closer to the game, look at La Rinconada in Peru. Sure, it falls under Peruvian authority, but its remote location (highest permanent human settlement) means that the national government has no actual presence there. The only power is the Corporación Ananea mining company, and they only care that the gold supply isn't disrupted. Sure, Peruvian law applies, but there are no police/military forces to apply it (or even sewage or running water - there are 3 communal showers for roughly 30,000 people - not including seasonal workers), so effectively it is an autonomous, and - unless mining operations are impeded - effectively lawless frontier town. Theft, rape, and murder are commonplace, and while the population is free to make their own local government (again, so long as mining operations are unimpeded), their time is consumed with simply surviving in one of the most harsh environments on the planet, so it doesn't happen. If you can defend yourself, good for you. If you can't, that's just too bad. If people decide to help you, great. If they decide to join in against you, also fine. Everything is permitted. The gold must flow.
I find the birth control situation interesting. You're right, most characters don't seem to know how easily it is obtained, but I have had NPCs abort pregnancies in my playthroughs. Admittedly, not often, but it does happen. Obtaining a gun I think could go either way. It would depend on how saturated the environment was before the collapse. If this is the UK, as the money symbol would imply, then I agree it would probably be hard. If the location were instead relocated to the US (or really anywhere in the Americas outside of
maybe Canada) and the symbol is just a generic for money, then I'm going to go with guns being pretty easy to obtain, if potentially carrying severe consequence for actually using. As for taxes, isn't a reason Sammy was able to get an apartment was because The Institute gave Oskar subsidies for rent? I thought that implied taxation on organizations at least if not on people. Still, if it means they are incapable of transitioning to totalitarianism, I'll run with it.