We have no choice but to wash them in cold, because we only have hot water in our two showers, and then only because we installed heater units for there. That is standard in homes here.
Of course, in Bangkok the “cold” water comes out warmish.
For many years we did not have a dish washer in our home. Our children took turns washing dishes and it was a struggle to get them to use hot enough water. I could always tell when they tried to squeak by with warmish water because the plates were always, always greasy when they did that. I didn’t matter what we ate that day if the wash water wasn’t hot enough the dishes were gross even after they had been “cleaned.”
I’m glad to have a dishwasher these days. It helps with chore time.