No LED-based lighting fixture uses a voltage regulator and a series resistor to limit the current through the LED.
The LED is driven by a current regulator; yes, it usually has a small sense resistor to measure and adjust the driving current, but that's something totally different from a resistor used to limit the current.
Remember, the 'D' in LED stands for (semiconductor) "Diode", which means that in forward conduction it has an exponential relationship between current and voltage. The only way to control the brightness is to control the current, you can't rely on the equivalent "resistance" (i.e. Vd/Id).
The premature failure of the LED bulb is caused exclusively by the embedded electronics degrading at high temperature. Since the LED is still dumping a lot of heat when working, the heat must be dissipated (hence puny LEDs and bulky, machined Al heatsinks) or the electronics get fried.
Guess what the drive to reduce the manufacturing cost will do to the quality of the LED bulbs?