We're talking about different isotopes of helium here.
The helium shortage here on Earth is with respect to Helium-4; the helium that you hear about being mined on the Moon is Helium-3, a very rare stable isotope of helium which is useful in fusion research and has potential to be used in future fusion fuel cycles.
So to answer your question, (1) we're not exactly close to harvesting helium from the Moon; (2) we can't really address the helium (-4) shortage on Earth with lunar helium (-3) as that's not practical; (3) there's easier ways of getting helium than extracting it from extraterrestrial sources; (4) the economy for He-3 is completely different (and currently nascent) than for He-4.