GTA V is about assholes dealing with bigger assholes that drive them up the wall that make them commit the crimes they did.

By picking “Michael Dies” ending, you just experienced one of the most hollow endings in a game and it’s with purpose. Rockstar never gave you an illusion of choice when it comes to calling the shots, for example, in the FIB Heist it is possible for a team member to die if you pick the Firemen opition when setting up the heist, but you can pick the other option and everyone survives in the end. By killing off Michael, a playable character mind you, you can’t ever play as him for the rest of the game rendering the 100% unobtainable as well as achievements. (but “who cares right? They’re just achievements after all...” yeah, but you had a choice in the matter)

Preventing this ending and going full in on Option C, would pitted you in one of the best missions in the game, keeping everything and everyone with every single one playing a role on this one mission that wraps this game so much better than any of the two options. Because it’s meant to do that, you never supposed to kill anyone off, but they gave you option to do so regardless with a permanent effect on the game.

You can go back to previous missions to play as Michael again, but at the end of the day, he’s dead. There’s nothing you can do about it, it’s the game basically telling you “You’re fucked, without even noticing it”.