juul pods are more sophisticated than you might think. the circuitry monitors the resistance change of the heating coil to estimate its temperature and adjusts the power to hit a target. this stops the wick from burning if it's dry (very unpleasant for the user) and delivers a consistent experience mostly independent of airflow over the coil. it takes a lot of engineering effort to make that work in such a small form factor and cheap enough to be disposable.