[K-Dog]

it's not from an external movement

All communications are controlled and this prevents the growth of any new movements says no external movements.

it's from failure of the basic systems holding the society together.  It's not individual states seceding, it's a general breakdown all over and a descent into some level of anarchy.

Some sort of breakup along administrative lines would fragment the country when one district does something the management of another district does not like.  This is failure of basic systems.

AFTER this, groups of people come together for mutual support and protection.

No, these are nothing like pioneers.  They have no skills to provide for their basic needs.  Everyone is beholden to the ruling authority for food.  Video games have not prepared anyone to grow food.