it baffles me how die hard zutara fans use the southern raiders episode to defend how their ship should've been canon when that episode has a clear depiction of how deeply aang understands and believes in katara in contrast to zuko.
from what aang knows about her as a person, revenge isn't ultimately what will help her heal, but he still lets her make that decision for herself and he ultimately ends up being right that katara is not a vengeful person and revenge wouldn't have given her closure. but the important thing here is he trusted she would stay true to herself.
meanwhile zuko doesn't even know what katara being true to herself would look like. he is surprised by her unwillingness to hurt the man who killed her mother, and learns from her and aang as a result. zuko literally acknowledges that aang was right to believe that katara wouldn't want to hurt him.