Because you can’t just start making someone else’s chip, you either have to own the patent or be willing to pay the appropriate licensing fees. That’s before you even get to the actual tooling to do it. There is no demand for this chip (yes I need one too). As a matter of fact they are still in stock with a few different bulk electronics suppliers — one place I looked at has 5000+ of them, brand new—but they require minimum orders of 1000 pcs. So if no one is willing to do that, it’s not considered high in demand. An electronics manufacturer has to demand it, i.e. cranking out hundreds if not thousands of units a day that use the part, not a few dozen, or even a couple hundred pedal geeks like us.