[jsnell]

They can't simply choose to do the same thing twice. They might need to double the machines, facilities, and workers trained for the production of those components. Oh, wait. Not just that component, but every other specialized component of the lithography machine, and every specialized input for one of the specialized components. If there's a single one that can't ramp up production and they can't find a substitute for, there's no point in any of them doing that investment.

Presumably a lot of the machinery needed to build these components is incredibly specialized too. That machinery won't be purchasable off the shelf. It will be ordered custom with long lead times, and (again!) could have bottlenecks in production that make it simply impossible to deliver in large quantities.

I'd bet (with no supporting evidence, just a gut feeling) that this industry needs to know five years in advance what the demand for chips in a given process node is going to be just to set up the supply chains to manufacture the right number of lithography machines. If that estimate is wrong, it'll take so long to build up that infrastructure that you might as well not bother, and just try to get things right for the next node.