[ethbr1]

The issue is time.

Say it's a YJ-83 clone, so around mach 1.4 terminal velocity (476 m/s).

Phalanx tracks at 10km, engages at around 4km.

So it has ~8.4 seconds of engagement time to try to destroy the incoming missile.

... And that's a relatively slow modern target. A P-800 gets up to mach 2.4. BrahMos is mach 3?

I'd guess the Navy would generally rather keep CIWSs on a hair trigger, and just space their ships further apart in combat situations.

And afaik, most of the CIWSs have been removed in favor of RAM, since the gun-limited engagement ranges don't make much sense anymore.