The only factories, that by "need" and not additional requirement are "lights out" that i have ever experienced, are chip factories, in particular the etching, photo-masking, implanting, etc.
Its only when non-automation become a "destructive" force, by lowering the yield, with extreme costs, lights out comes to fruition. And even then. The additional costs are staggering. All technology is not "off" the shelf industrial equipment, but special designed equipment to reduce wear, tear and particles.
Another case is, were the equipment or process is dangerous to humans. Battery manufacturing or chemical industry, come to mind. Usually the lights out there is a Encapsulating layer around the machinery, with close direct observation by human overseers.
Yup. I've seen a planned computer assistance step get abandoned because we never figured out a way to work around thermal expansion issues. The objective was to laser-paint a drawing of what they were to build, but we couldn't keep the laser from drifting. (That was ~20 years ago--now I would solve it by putting a camera with the laser, noting the discrepancy and adjusting the laser.)
Factories are vast assemblies of atoms constantly entropically smashing and grinding themselves into dust.