People like to joke about this but the reason it's called a "boiling vessel" and not a "Tea maker" is because it's incredibly useful other than just making tea, to the point that the US has also added them to many modern vehicles.

On demand hot water, from the safety of your combat vehicle, is a genuine war innovation on the same level as canned food. Especially now that combat vehicles are aiming towards having more robust electrical systems makes it trivial to implement. Hot water means hot food, means warmth on a cold day, means sterilizing sketchy water sources without chemical tablets, means you don't have to light a visible fire to make your coffee, means you keep morale way higher. Your troops are now cleaner, better fed, happier, more motivated.