Chicken rice is actually one of the better hawker choices for protein per calorie, but only if you respect the rice. That rice is not plain. It is cooked in chicken fat and oil, which is exactly why it tastes so good and exactly why it carries more calories than you would guess. The chicken itself is lean, especially steamed. The rice is where the damage is.
Steamed chicken (no skin) plus a normal scoop of rice is a genuinely solid meal at around 33g protein. Roasted chicken with the skin, or the fried version, adds 100 to 150 calories of pure fat for almost no extra protein. Same plate, very different math.