I agree with you in concept, but I think certain suits wouldn't make sense with that functionality. The skin-tight EVA suits with the small helmets, that have just a few minutes of oxygen I feel wouldn't have the room/capability to allow the user to eat/drink hands-free. But there are several suits that are bigger, and designed for extended exploration sessions that have tons of oxygen storage and larger helmets/built-in backpacks that would absolutely have other life support like food/water built-in.

The smaller suits are designed just in case you need to EVA, and many ships have dining areas so you can pop the helmet off and enjoy a meal in comfort.