I hear that. I the plant I work in, you would not believe the carnage that is caused by something is simple as a brownout, even if it lasts a split second. I have spent hours recovering machine operations over that.
We had an acre of CNC tools running, and lost one phase. Some of the parts were titanium. It took days to recover, and still a lot of scrap was made.
Semiconductor wafer fab lines may be the worst case. A power outage there can break equipment and spoil almost all wafers in process. That could be hundreds of millions of dollars lost from a single outage.
Scarce wonder that a wafer fab will spend, say, 20 million on a complete factory UPS--that is, about 1 percent of the entire plant investment.