Yeah...all things considered, the CUI is strangely in a very convenient position to be deposed in Worm. A maximum amount of power is centralized and focused inward, and the bloody oppression occurs at the hands of a relative few. Even the Yangban make heavy use of coercion and brainwashing, so if you can recapture some odds are they're unwilling victims and can be 'saved'. For the most part the people live in fear of the government, and do not give it any more legitimacy then it takes through intimidation and oppression.
With IRL nations historical and modern or other Earth Bet examples (in particular parts of Africa and Europe)? There's a lot less centralized power, and a lot more propaganda and indoctrination among the populace. Even if a government is unquestionably detrimental (and few rarely can be while still being functional), there will be believers and true 'patriots'. Taking one of them down, while probably still possible, would be a very messy and difficult affair to clean up.
The CUI? Assuming you can clear the admittedly high barriers of ability to deal violence and project power, their domestic situation is remarkably simple (their neighbors not so much, but they'd be fine so long as the military isn't totally destroyed and idiots don't have nukes).