Weapons from ww2 are still being used in warfare to this day.[0] You fight with what you can get your hands on, I guess.

Edit: Also military logistics are not following the same pressures for upheaval and progress as civilian organizations. During my compulsory military service I remember getting handed a bedsheet with the year 1933 embroidered on it. Looked liked it had never been used. We were also trained in usage of out-phased rifles on top of our normal weapon training. Somewhere they had a huge pile of old weapons, should they ever be needed. It would not sunrise me if they still have the Garands on store.

https://atwar.blogs.nytimes.com/2010/09/15/whats-inside-a-ta...