When I first moved to the UK in 1993, I couldn't believe people didn't rinse dishes. Plus, there were times when DH used a glass, but just rinsed ....not washed....and I had to snatch it back.
He thought I was being foolish when I insisted on a dishwasher. Now he wouldn't be without one.
I remember one neighbor saying she had a better dish washing liquid that was low suds, and that meant she didn't need to rinse the dishes. I said...nothing....what can you cay to that?
I had another friend who couldn't understand why she had to wash dishes before use when they came to their holiday house in Portugal. She said "I wash everything, but there was mold all over them". And she was maniacal about cleaning. Had the dishes been rinsed properly and dried before going in the cupboards.....I suspect no mold would have developed.
If I'm serving soup (or whatever) I don't want to see pools of residual soap on the surface, and I definitely don't want to eat residual anything.