Well, for MLCC caps specifically, 6.3V is definitely not going to cut it (that's less than the voltage across 2 LEDs, and there will be more than that in series). You'll find that 100uf in 200V ceramic caps will be substantially more expensive ($10 - $100), plus you get fun effects like ceramic capacitors have less capacitance the higher the DC voltage across them.
Electrolytics are used when you have no choice, and if you are trying to store a large amount of charge in a small volume (especially on the cheap), you have precious little options.
Thanks! I was thinking of a single LED. Looking at other teardowns where the actual light emitting elements are shown, I see that bulbs contain multiple LEDs.
Electrolytics are used when you have no choice, and if you are trying to store a large amount of charge in a small volume (especially on the cheap), you have precious little options.