I think you missed in your list that new hot water heaters have a much lower temperature limit. I’m not 100% sure on that, but I read a lot of frugal blogs, and that has been mentioned several times by commenters when the various ‘use cold instead of hot water to wash’ suggestions come up.
I use cold and warm, but do occasionally use hot. Irks the heck out of me....
Have not heard the water heater business. Must have something to do with scalding. Just pull the thing out and use cold or boil a pot or two when someone has a baby.