Brock's departure had the misfortune of sharing the same episode as Dawn's departure, and as we know, the writers had to focus moreso on Dawn leaving even though she was on the show far less than Brock was.
Brock had been in the anime for 13 years aside from Orange Islands, he was Ash's longest lasting travel companion in the series and had somewhere around 600+ eps in his total run.
DP191 focuses on him deciding to become a doctor, and his departure is after the end credits, where he and Ash shake hands before he leaves. His actual departure didn't last longer than 1 minute.
Do you feel it was a good enough sendoff for a character there that long? Should the writers have made a bigger deal out of it? Should they have done a character montage? How do you feel about the way it was handled?