The problem is helium cannot be contained, and it goes up until it leaves the Earth. It never binds to any element that could "anchor" it to our planet. Compar

The problem is helium cannot be contained, and it goes up until it leaves the Earth. It never binds to any element that could "anchor" it to our planet. Compare with liquid nitrogen: you can liquify air, use the nitrogen that sooner or later will go back to the atmosphere, but it rarely leaves the planet. So you have a cycle.