But lifetime support doesn’t help if the parts for your machine aren’t available anymore. If your 20 year old machine breaks and there aren’t parts available to fix it, you might get offered an equivalent replacement. If your old chip masks are incompatible with the replacement machine, you’re not immediately able to make what you need. So for some companies, having lifetime support might not help with the manufacturing slowdown when an old machine breaks.

I can't vouch for the parts, but they supported machines from the eighties. This is not some cheap consumer product that has half-lifetime of 13 months.

The parts were made by humans once, they can be made by humans again. The only question is is it worth it

Underrated comment. Though the "worth it" bit is the trick.

In my estimation these older parts that "just werk" should be getting inherited and iterated on as a public good.

The idea that means of production should phase into public trust tends to get everyone in a tizzy though. I'd like to see a public "foundry of last resort" that focuses on being able to make anything.

Not completely sure on this one, for example how the Romans had better concrete than we have now, even despite all of our scientific advancements

We know how they did it, it just does not scale, because it is not worth it causing a volcano every time we need some more ash.

Most 20-30 years old machines on the market are Japanese, ASML wasn't that dominant in the long tail market up until DUV era.

And Japanese almost as a rule have whack a good leasing, and service business, including replacement parts for close to 30 years old equipment.