This isn't my field, but I'm not sure what's the excitement about an Arizona plant that will optimistically start production a year later with an older process.
A good example is the automotive industry. It doesn't typically move quickly or frequently onto newer generation processes as that requires R&D time and other expenses. However, these have been some of the worst shortages, with auto manufacturers still impacted by lead times (although, this is starting to clearing up fwiu).
Targeting the current-best process, rather than the next generation, alleviates some compounding of risk that would be incurred by logistics concerns of turning up a new site and putting that new site on a process that they don't yet have full confidence in because it's not seen production yet.
The chip shortage in products like cars has been for much simpler chips, AFAIK.
The article says Apple, AMD, and Nvidia are looking to source from the new plant. Aren't they canonical examples of companies that are always looking for the latest and greatest? Why would they be interested in an prev-gen chip?
Defense also uses older chips. Don't ask what kind of chips are in Amraam missiles or the F-35 -- although the F-35 is getting a technology refresh now (after a 14 year production run).
Only in bleeding edge consumer devices does it make sense to keep changing chips. In other systems, production runs can last 20 years and the life of the asset can be 40 years or more, and you want the same spare parts available throughout the entire expected life of all assets produced. And then when you look at fixed assets, such as thermal power stations, then you are looking at even longer time horizons.
1. What's so exciting about a prev-gen fab possibly being completed in 2024?
2. Who will buy the chips produced by the 4nm Arizona fab, and why?
The only plausible answer offered for 1 in this thread has been that it's too difficult to jump straight into the bleeding edge, and this is the most the US can do to lay the foundation for an eventual catch-up with the state of the art in chip fabrication.
My guess is that the decision to build fabs in the U.S. was the result of geopolitical strong-arming by the U.S., but TSMC will still find buyers and that the fab will at least pay for itself.
Intel has sinking in at least technical leadership for a long time. It's obviously a priority a need for the us to on-shore more chip prod.
CPUs and GPUs get all the press, but there are dozens of other chips used in even the latest models that use older technology. For all we know Apple could be buying those chips for USB cables, or pencils.
From a strategic perspective, it is absolutely important that you have the capability to build chips in your country, of a reasonably modern node size. You need this for weapons manufacturing, for a working government apparatus (governments use computers now), for sending messages to your population. And if China bombs Taiwan, then this fab will become the cutting edge, instead of you having zero chip manufacturing capabilities.