Of course, producing the EUV beam in the first place has also not been duplicated and it's Californian technology.
Intel 18A has a different strategy all together. I mean, it's not like they're saying much about it, but from the little we know, it's very different.
Free electron lasers are not hard at "mere EUV", and the accelerators to feed aren't either, it's just that an efficient setup requires recycling the beam which means bending it back which means a large (factory hall sized) accelerator at the beam energies needed for good EUV light.