Neat right up, I think you have some interesting insight here. I don't know the fab scene nearly as well, but I think you may be missing a stage (purposefully?). After exponential growth fades, the next stage will likely be more linear, which will have it's own consequences. What you're describing here sounds more flat or logarithmic (think battery tech from 1980 to 2000). Not saying it won't happen, but I think linear growth will happen first and have it's own separate impact. For example, we may see a stage where hardware tends to grow in price rather than decrease because economies of scale will also follow the linear pace. You can no longer just "throw hardware" at your capacity problems but companies will try and the ones with the deep pockets will continue to do so.
With linear shrinking factors, and keeping the current exponentially growing costs, I'd expect fabs to specialize, a few going in the route of smallest possible features at a huge price, and most going in the route of commodity, low price chips.
