below 25w doesn't have to be pfc....not at all (in Europe).
However, led lightbulbs with significant capacitance following the mains diode bridge are damaged if connected to a triac dimmer (due to resonance of the emi filter inductances and the electrolytic cap.)...therefore, even low power led lightbulbs (eg 7w) are made fully power factor corrected as then they don't have much capacitance after the diode bridge.........
so, due to these triac dimmers (which , incidentally are only actually meant for use with incandescent), virtually all led lightbulbs are made with pfc, apart from the really really cheap ones.