re: After rewatching The Wire, the ending for Duquan was the most depressing for me

The school season(s) are underrated I think. The show's character of Baltimore couldn't have been told without it. It was so perfect for the series to demonstrate the plight and path of the other characters having come up through that system and city. It's an autobiographical account of sorts, 20+ years ago which continues today after 4 Presidencies and multiple shitty mayors.