Where The Real Chip Shortage Is

This video seems to be doing much better job at explaining the problem [1]. Long story short there's high demand for trailing edge (50nm+) tech, but it is not worth investing in building more of these for number of reasons mentioned in the video (huge investment, long time, and despite high demand it's still only low percentage of profit compared to cutting edge) I suppose prices must increase but likely there are some long term contracts in place. 1. ▶ this video

Under most circumstances I can't imagine a reason to bother powering on a 10 year old system, short of nostalgia. The costs of running it will quickly eclipse the costs of buying something newer and more efficient. Of course, there are plenty of edge cases, like needing something bare metal that has a particular sort of software compatibility or IO requirements. Some industrial computers still run 486 chips with ISA buses for this reason. These sorts of systems will have been engineered with longevity in mind from the outset though. Other edge case, just for fun: embedded style systems like the Raspberry Pi. These are tiny, low power, and can be used for specialty purposes for ages. They are also engineered on nodes and setup in a manner that will likely leave plenty running successfully in 10-20 years' time as it is. It is really only since we've entered the era below TSMC's 7nm node that longevity has become much of a concern at all. It would take a whole essay to even TLDR the constraints of why that only becomes very relevant in the period where those nodes start to become known as "mature", and this is already enough of a tangent, so I'll just leave this breadcrumb of a presentation on the lifecycle of silicon process nodes: ▶ this video

The short answer is that they are not building more fabs for non-leading edge processes, like those used by STM32. There is an interesting video about this: ▶ this video