You have MILLIONS of transistors in there, and they're applied with a process that's like photography. So you're asking them to go to the biggest zoom possible, right away. But unfortunately, every time you zoom a little bit more, you could have more errors. 1% errors means 10,000 transistors are bad, and that means that chip is shot, no good at all. Your computer could go haywire if maybe even a single transistor is bad, the error allowances are extremely small.

So if you look at it historically, look at what happened when they sent up the space telescopes. They had issues with the Hubble lens (zooming). Every time you step up in technology, there are errors that have to be worked out. Errors that could destroy your entire set of chips, resulting in billions of dollars in costs.