AkshatArpit
You are worried about people quiting your story but the solution to this is imprisoning your audience in the first place. The main reason people quit a story is because it offers nothing to follow. Just the ending of this chapter is enough to make me want to follow the next because it was somewhat unexpected that he would steal.
I do not think the US government would dissolve its army like that even if people became powerful. It would be highly unpopular among the general public and something both democrats and republican politicians would not want to happen (especially republicans since it is part of their ideology). Even if both sides argue about military budget allocation, maintaining the military would be a bipartisan agreement. Furthermore, a military would be important in deterring other countries from attacking. That is why they exist. I do not think the appearance of dungeons would change that. What I think would likely happen would be a massive conscription by the government to force those with abilities to enlist (which the public would support in a crisis like this). I don’t think guilds would exist at all but maybe something similar would exist within the military. After the chaos settled and conscription ended, plenty of people with abilities would still voluntarily enlist. A massive military reform would likely happen to accommodate adventurers while research funding would shift towards combining magic with technology to create powerful weapons. This all based on my knowledge of US politics, the military, and general public opinion. I am sure this could be applied to most countries as well. Even myself would be fearful of abolishing the military. This is the most pragmatic approach I can think of that makes sense.