Ultimately, we must concentrate on two areas: the Capital Region and the Southeast Region

Balanced development? It sounds nice, but there are no answers to why we should do it or how we will achieve it.
For a region to survive and function properly,
the entire life cycle must rotate there: finding a job, meeting friends, meeting romantic partners,
having children, watching those children grow up, attending university,
and finding employment within that same region.
Claiming it is "balanced development" just by moving one thing to Daejeon, one to Gwangju, and one to Daegu is truly irresponsible.
Once the youth move there, who will they meet after work, and who will they date?
It is impossible to put down roots and live in those areas.
We must either go all-in on the Capital Region or select one more location and move everything there in bulk.
Only then, even if someone finds a job in that area, they can meet a partner from a different company,
have children, buy a house, send them to school, and those children can
attend local universities and find jobs in that same community.
The reason Sejong failed is
because it is too close to Seoul,
and because only civil servants were relocated—and even then, only partially.