That's doesn't take into account technological progression.Yes.... For such a big conventional warhead to hit accurately it has no other option other than to slow down considerably. It can work if enemy air defence is s**t..... But if it isn't you would need such missiles in huge number fired in Salvo to saturate enemy defences.
BM-04 with HGV warhead is shown with under 30m CEP.
And tecg progressing is a continuous process.
Already exist, and hyumoo 5 missile is an IRBM category size wise.ICBM ones makes no sense. However, SRBM or MRBM is something to look at. It is something that can be developed and inducted if needed. Presents itself as a good conventional option as I stated in my post. Also, we can look at a much more realistic development to deployment time for it. It can be fielded by the next decade if needed.
The Hyunmoo-5 is a South Korean "monster" ballistic missile designed as a conventional bunker-buster to destroy deeply buried underground facilities. Unveiled in October 2024, it carries an unprecedented 8-ton warhead and is being deployed to counter North Korean threats through massive conventional retaliation.

