Cosmically abundant, but not abundant on Earth. Or any terrestrial planet, for that matter. The problem is that helium is both extremely light and chemically inert, so it quickly escapes into space from any celestial body smaller than a gas giant. Earth lost all of its helium almost immediately after it formed.

The helium that it does have is stuff that was produced deep in Earth's interior as a result of radioactive decay. When an atom releases an alpha particle as part of a radioactive decay chain, that's a helium nucleus. The helium seeps upward through the crust and gets trapped as a contaminant of certain natural gas pockets. The helium we harvest industrially is extracted from those particular natural gas wells as a byproduct of four billion years of radioactive decay. When it gets released into the atmosphere - such as when it's used in a party balloon or blimp - it disperses into the upper atmosphere and is lost to space. One use, then it's gone forever. Eventually those natural reservoirs it's being extracted from will run dry and that'll be it - no more helium available on Earth.

I really hate party balloons. What an utterly ridiculous waste.

Not on earth