It isn't exactly wasted. Like you said, it's an element. Short of any nuclear reactions, it won't be destroyed (plus I'm not entirely clear if any useful reactions actually consume helium).

Helium in balloons is returning to the atmosphere. We can re harvest it if we want. While that sounds wasteful, it might actually be more efficient than trying to purify lower grade helium.

I'll put it this way. If the helium in balloons could be easily purified to what they need for industrial uses, we wouldn't be using helium in balloons. Purification industry would drive the price of it sky high.

EDIT: Ignore most of this, I didn't do my due research.