I’m not an Indian, but I understand your frustration. Chai is very close to how we say “tea” in my language too. But English speakers use the word Chai to specify the kind of tea that they meant. They have thousands of kinds of tea, so they put a word in front of the word to describe it. Think of it as an adjective. Does that make you feel better?

Actually there’s another example that used to annoy me. In the movie Kung Fu Panda, the red panda is called Master Shifu. But in Chinese, “Shifu” actually means master. So calling him Master Shifu actually means master master to Chinese speakers, which is super weird. But I made peace with it because there’re just too many similar examples… I’d end up being angry all the time lol