China tests its latest smart submunitions technology aboard a DF-16B Ballistic Missile.

[BoQ77]

Except it's all about stand-off attacks these days to reduce risk to launch platform, and ballistic missile is about as stand-off as you can get. You're not flying out to the area of operation to look for targets of opportunity. The targets in the area are already predetermined before the strike.

You lost the ability to track the aftermath.

 

[Kompromat]

Smart sub munitions were displayed at Zhuhai airshow last year.

 

[nang2]

Back in 2010, Taiwan stated China aimed about 1000 ballistic missiles at the island, growing at about 200 a year. Of course, that info is 5 years out of date. Since then, China has developed a vast array of other strike methods.

You believe that? Don't they know these missiles are like GPS navigators? Missiles aren't pointing at anywhere until someone enters the coordinates, which can be done right before launch.