The simplistic answer to why a LED have less throw than incan is something known as the "inverse square law".
It's covered in High-school physics and it's simply, "double the distance, and quarter the brightness". In the texts, it is usually qualified with "only applicable to point source".
When the radiating body is NOT a point source of radiation, there is something known as "conservation of radiation", which is easily demonstrated by lighting a room with a bare lightbulb, and walking away until the "glare" is comfortable to our eyes. Now replace it with a frosted bulb (which distributes the output over it's entire surface) of the same wattage and stand at the same spot as before. Even though it is now "softer", our eyes wll receive greater intensity at the distance where the naked bulb "point-source" starts weakening.
There is a "Rule of 5" which states that up to 5 times the diameter of the radiating body, light does not obey the Inverse Square rule, instead it only decreases by 1/2.
To take advantage of this, flashlights use big reflectors - to maximize the radiating surface. Most of us know this already - over distance, a larger reflector will ALWAYS outperform a smaller one, given similar lights.
Big reflectors don't help LEDs as much - they don't have the full 360 degree radiation for an even beam, and optics loses even more energy. But worse, because it is virtually a point source, its light is already diminished by the time it reaches the reflector. In comparison, the filament in the incan bulb has a much larger radiating surface, so it can enjoy the 'conservation of radiation" further.
In general, the best light reflectors will have a radius of no more than 5x the filament length.