As a guy that went through cooks AIT in the Vietnam era and then was a Reserve Mess Sgt. I can tell you what happened — civilian cooks.
by the mid 70s civilian cooks began to make up a lot of the mess hall employees and by the 90s that was the vast majority.
In civilian life I built a lot of projects on military bases. Some had 16 mess halls with only two predominantly staffed with military cooks. That is where I paid to eat lunch, not the ones that might have a few military managers and civilian cooks.
I would think that skills training they could still get enough interested enlisted in the volunteer era but I don’t think they wanted to have cooks make up a significant percentage of the forces.
I was a good qualified rifleman as well and ran big consolidated mess halls feeding over a thousand man each meal as well as forward tent based field kitchens.
Thanks for sharing that.
I left the army after I came home from VN so missed all that.
I was a grunt and we did pretty amazing things with condiments stolen (with a wink and a nod from the mess sgts) from mess halls to make our C rations tastier. We had no MREs in those days.