They are. They're usually called CRAM or CIWS on ships (Close in weapons system)...

Aerroon on Aug 31, 2020 | parent | context | favorite | on: Drug cartel assassinates its enemies with bomb-tot...

They are. They're usually called CRAM or CIWS on ships (Close in weapons system).[0] They are used as the last line of defense on modern warships against missiles and other threats.

Here you can see one of them in action:

https://www.youtube.com/watch?v=KsVUISS8oHs

[0] https://en.wikipedia.org/wiki/Close-in_weapon_system

sudosysgen on Aug 31, 2020 [–]

They are also ineffective against more than a handful of threats.

They work okay against mortars and dumb munitions, though.