This is like asking: People who eat food for the calories, why don’t you just eat dry primate food pellets?
Because there’s a big upside to enjoying the experience of drinking coffee with few downsides. If coffee was just caffeine dissolved in water it’d be a very different story
Personally I only care about calories, I’m on board for food pellets if they actually worked and were healthy.
You may be a robot in that regard but you’re clearly aware that people enjoy the taste of food and coffee, right?
That’s why I said for the caffeine and not who enjoy coffee.
The same reason smokers don’t just wear nicotine patches.
There’s much more to the ritual. The caffeine may be part of it, but pulling in the other senses: the flavor, the smell, the warm mug in your hands, all add up to much more than a dose of caffeine.