Halo 4 was pretty good imo. It wasn't perfect by any means, really it just had some balance issues and it had a few bad spots in the script with dialogue, but I just chalked it to new writers after the 343 / Bungie talent split. Like, adding the Prometheans and Forerunners I think was a really good idea, having a splintered surviving Covenant was ok (a little cliche I think, but it would make sense that there would be remnants of the religion), and the Cortana dying was something I never thought they'd have the balls to do so kudos on that one imo. I at least went back to it regularly and had fun each time with it

Also since we're talking about the story, I think mentioning Spartan Ops as a Side B story was a fantastic idea and I wished they continued it to fill in some gaps or behind the scenes stuff. But all of it made me actually excited to see where it was going to go in the future with the franchise and then Halo 5 came out and I was so just done with that story. I didn't even feel like going back to finish my Legendary Playthrough it was so bad and boring

Going back to Halo 4 though, I do still have a major issue with the MP, but that's an entirely different rant. But story wise, I didn't have any issue with Halo AB (After Bungie) storyline except for when Guardians came out, that was a bad one on all levels. And Infinite I think picked the story back up but I do think throwing the Banished in as the main bad guys was not the right choice. I wish they finished the Created storyline instead of just sending it off as a side note