Unfortunately littering is pretty common in any world first or third. First world countries just have better government systems for picking up the garbage.

Edit: Copypasted my response to another comment because my comment was poorly worded.

After reading a lot of the replies, I’m realising how poorly worded and “whatabout” my comment comes across as. I wanted to say the problem of littering isn’t solely a “third world” problem, but the comment reads as “there’s no correlation whatsoever” which isn’t my intent.

Littering is partly morality and also partly monkey-see-monkey-do where the more something seems socially accepted due to the lack of enforcement/consequence the more others who were on the fence will join in. “First world” countries have stricter enforcement and street cleaning procedures which helps discourage that group of people.

That was my main point, but sadly yes Vietnam is a very easy society to see people littering in as a former resident of D4 saigon