I mean, Halo started as a game. The fans of the game are definitely right, the show was mostly garbage. A generic scifi show with mid to bad writing, with the Halo IP slapped on top as an afterthought.
The had the story handed to them on a silver platter. They could have more or less followed the cutscenes of the game and easily have had a show that would have been a home run with the fans, and with people that didn't know anything about Halo. Very minimal changes would have been needed for this, since Halo was a pretty tight story anyway. Could have been about 45 minutes to an hour long for each mission in the game as an episode of the show, for a banger 9 episodes.
Instead what they decided to put out was de-canonized very quickly and deviated so drastically from the source material, I would even call the Tomb Raider and Resident Evil movies "more true to the source material."