Red Dead Redemption 2 received enormous amounts of critical praise upon its release, with many people singling out its incredible story for particular praise. Not only was the story intricate, deep, and very well written, but it was populated by a slew of memorable characters who were expertly portrayed by a team of capable actors.
Arthur Morgan is one of the best protagonists ever seen in a Rockstar title, and many players found him a relatable character. He holds numerous flaws, and he's a very sad and very tragic figure at his core. In fact, the sad aspects are nearly too much to count.
Tuberculosis
Perhaps the saddest thing about Arthur Morgan (at least in regards to the on-screen events) is his diagnosis of tuberculosis. The diagnosis rocks Arthur to his core and prompts him to become a better person in his last days on Earth.
While Arthur remains stoic in front of his friends and family, he secretly harbors incredible fear in regards to his impending death. Not only that, but Arthur physically beings wasting away, becoming skinnier, growing physically weaker, and developing a paler appearance.
Terrible Final Days
Red Dead Redemption 2 is ultimately a tragedy, and its ending is suitably depressing. Rather than enjoying his final days in peace with friends and family, Arthur is subjected to a slew of problems.
The gang is falling apart under the dictatorial machinations of Dutch and Micah, they're stuck in a war against the United States Army, and most of them perish in gun battles and internal fighting. These aren't the final days that Arthur was hoping for.
Lost Son
Late in the game, it's revealed that Arthur once had a son. Isaac Morgan was born to Arthur and a young waitress that Arthur had slept with. Despite always being on the road with his outlaw gang, Arthur supported his family by mailing them money and visiting from time to time.
By all accounts, his family life was quite solid. However, tragedy struck when a thief killed both the waitress and Isaac in a home robbery - an event that left Arthur's soul permanently stained.
Rough Upbringing
It's no secret that Arthur Morgan didn't have the best family life. His mother tragically passed away when he was young, and his father failed as a single parent. Rather than supporting and loving Arthur, his father remained emotionally distant, committed various crimes, and was eventually arrested for larceny.
He eventually died in front of Arthur, leaving his son both homeless and an orphan. It was then that Arthur, negatively molded by his father's actions, was picked up by the not-so-great role models of Dutch and Hosea.
Separation From Mary
The story of Arthur and Mary would make a fantastic movie about divorce. Arthur and Mary became engaged at a young age, but their entire relationship was fraught with drama.
Arthur and Mary's father constantly fought over Arthur's outlaw lifestyle, and Arthur's life of crime constantly got in the way of their mutual happiness. He and Mary eventually split and separated, with Arthur seemingly choosing a life of crime over domestic bliss with Mary.
Betrayed By John
Just when Arthur needed John the most, John personally betrayed his good friend and surrogate brother by running away from the gang. John was feeling too much pressure with his newfound family and needed some peace, and Arthur found this incredibly selfish.
Not only that, but Arthur was left hurt by John's actions considering the love he carried for his late son and the rocky history he shared with his own father. It brought up past memories that Arthur simply didn't want to confront.
Very Lonely
Even though he belongs to a large outlaw group, Arthur Morgan is a very lonely man. He's not especially close to anyone in the group (aside from maybe Dutch, Hosea, and John), and he shares a very nebulous (but polite) connection with most of its members.
Furthermore, Arthur is constantly on the road by himself, spending nights upon nights all alone by a fire. Arthur doesn't even tell the group about his TB and impending death, either through pride or a lack of personal connection.
Low Self Esteem
Some of the greatest Easter Eggs in the game lends further depth to the character of Arthur Morgan. It's very obvious that Arthur has self-esteem issues, not to mention a very low opinion of himself as a person.
His journal contains a few clues pointing towards this truth, and if Arthur speaks to himself in a mirror, he will often call himself "ugly" or degrade himself in some other tragic manner. Arthur is a stoic man, but it's clear that he hurts underneath.
He Dies Alone
Red Dead Redemption 2 contains quite an emotional ending, and regardless of player choice, Arthur Morgan will die. And it's made even more tragic by the fact that Arthur dies alone.
If the player has low honor, Arthur is directly betrayed by Dutch and killed by Micah, either by being stabbed or shot. If the player has high honor, Arthur literally dies by himself while watching the sunrise. No matter the ending, Arthur dies without the comfort of friends and knowing that his family has utterly collapsed.
He Knows His Life Is Ending
In more ways than one, Arthur Morgan knows that his life is ending. In the more literal sense, Arthur is diagnosed with TB and is forced to live out the rest of his life knowing that his time is short. TB was a death sentence in the late 19th century, and Arthur was fully aware of that.
In the more metaphorical sense, Arthur knows that his outlaw lifestyle is coming to an end thanks to encroaching civilization, and even though he humors Dutch's outlandish plans, he knows deep down that the time of the outlaw - and the time he has with his "family" - is over.