Ultra clean rooms with massive air handling systems can't recapture all their helium?

Or is this just a temporary thing based on where processing is located?

Helium is almost all captured from gas wells by cryogenically liquefying the nitrogen out of it. I guess you could do technically do that with the fab's air but it is a LOT of volume of air to liquefy and likely costs more than even inflated helium prices.

Most helium from most wells is simply vented because it is expensive to separate even with its relatively high concentration, and I imagine even the best case scenario for capturing it from a fab has abysmal concentration of helium. But because most of it is vented it also means if the capital is put down to build more helium separators on gas wells it wouldn't take long to increase supply. Short term for a year or two it can be a problem, but beyond that it is simply a cost versus demand issue. There is neither a technological nor source limitation, it is a pure capital investment limitation.

Helium is actually pretty hard to keep ahold of, being a very light and small noble gas. It can diffuse through a surprising amount of materials, flow through far smaller cracks than you would expect, and is quite hard to filter out of a mixture of gases.

AFAIK they recapture most, but recapturing all simply isn't possible / financially feasible. And they use a lot of helium, so even if they capture most of it, the losses are still higher than the currently available supply.