...there are people serving in the artillery...
One of whom would be my son. Not too many years ago (call it the 'oughties'), when he was in Artillery Officers' school, he was first taught how to calculate the aiming of his artillery pieces using tables and a slide rule. After he passed that test, he was introduced to the computer method. He understood the reasoning behind this very clearly. Computers have a lot of little parts that all have to be undamaged and correctly functioning. Slide rules have three (the two engraved bits and the slidey cursor) and tables just need to be present and readable.
When everything goes to sh*t, you want to be able to fall back to something more reliable than a fondleslab for communication. I don't think they'll be taking those blinker lamps off the ships too soon. Though my coworker, who's an enlisted radioman in the Marine reserves, says they did not teach him Morse, but still issue semiautomatic keys to radiomen. The brilliance of the military.
// the one with the Amateur Extra license (20wpm) in the pocket