In Asian culture, out of respect, elders are addressed as Uncle or Aunty. If they are close to the family Uncle or Aunty is followed by the name e.g. Auntie Li or Uncle Dev. I like this and I hope the future generations continue to do it. There’s something really warm about being addressed as a relative even though you’re not officially one.
When we visit our friend’s parents we also address them as uncle or aunty. In our culture it’s a form of respect and courtesy. It might cause a bit of culture shock for expats who are not used to this but I hope they like this aspect of the culture.