I won’t argue that it is the most hygienic way to clean laundry, but I doubt it is necessary on a day to day basis. Most people don’t get their underwear or bedsheets that dirty. Hospitals, nursing homes, daycare centers - sure. But not your normal household unless someone is severely sick.

We personally only wash dish towels, cleaning supplies and similar stuff at 90°, the reason being that the 60° program on our washing machine uses up just as much energy as 90°, and we don’t need to use extra hygiene detergent when we do that.