Oh goody, is this another chance for me to explain why Halo 4 is terrible and Halo 5 isn't?
I disagree.
I believe that Halo 5 improves on many of the complaints that I had about Halo 4, but then went onto make different, but equally terrible choices in other areas.
Take the campaign for instance. The downfall of Halo 4's campaign was that a lot of the important context of who the Didact was, and what motivated him, was locked away in the books, so many players just ended up plaything through the game, with no idea why this evil guy was doing what he was doing. In Halo 5 though, the story was easy to understand, but the issue was that the game was marketed in one way, and then the game presented an almost entirely different story - not to mention that you barely even played as the Master Chief.
Different, but equally terrible.
I disagree. Halo 4's campaign is worse.
You're right to point out the issues with the Didact, but that isn't the only problem Halo 4 has with its narrative. The other problems are...well, everything. Seriously, it's easier to list what Halo 4 does well (the relationship between John and Cortana) rather than what it doesn't (pretty much everything else). For instance, you're right that it doesn't explain the Didact well...nor does it explain why the Covenant is apparently your enemy again, or how John knows Lasky, or why human tech has improved so rapidly in just a few years, or, well, anything.
Halo 5 isn't without its own issues, but the marketing isn't among them. Yes, the marketing was misdirection, but that isn't the fault of the game itself. To borrow a tired metaphor, if my friend tells me we're going to a steakhouse, and instead takes me to a salad bar, while I may be disappointed, that has no bearing on the quality of the salid itself. I'd also point out that Halo 2 had similar misdirection (hyping up the invasion of Earth, when we quickly leave the planet in the game's story), but even that aside, if the marketing was misdirection, again, that's a criticism of the marketing, not the game itself.
Also, I really don't get the idea that in a Halo game, we're obliged to play as John. At this time of writing, there's 13 Halo games. John's been playable in 5 of them. The series is called "Halo," not "Master Chief." Even if you revise that argument to include only the core games (whether Reach counts as core is debatable, but I'll let it slide), then yes, he's been playable in each of them, but we split time between him and the Arbiter in H2, and no-one complained then. Well, I mean, I have, but only in the gameplay sense. I don't like most of the Arbiter's levels, but it definitely serves the story.
Where Halo 5 does reach above Halo 4 though, was its multiplayer offering. Gone were armour abilities, loadouts, perks, and killstreaks, and back were equal starts, and on-map weapon pick ups. Halo had at least gained some of its identity, which Halo 4 quickly abandoned. And that is not even to mention the drastically improved Forge, and introduction of great community features, like a custom games browser.
But on the flipside, the entire progression system of 5 was based on microtransaction lootboxes. Swings and roundabouts.
Ultimately, I would say that Halo 5 is a superior game, solely because of its multiplayer, though that isn't exactly high praise.
Again, I don't think these 'sins' are equal.
This is very subjective, but I LOATHE the loadout system of Halo 4. I'm not against loadouts or class-based FPS, but Halo is an arena shooter. So you've got this weird mix-up of arena maps where you can find weapons, while also having loadouts at the start of the match. It was stupid in Doom 2016, and it's stupid here. Halo 5, on the other hand, goes back to arena FPS, and gives the player new movement abilities, from the jetpacks to the ground-pound. And if we're talking about microtransactions, again, this is pretty academic. The only way they can affect the gameplay in any manner is in Warzone, and you still need to earn the right to use them. I mean, yes, I can splurge on Scorpion cards for instance, but in the match itself, I need to get my character to the right level to deploy Scorpions. And the drop rate is so generous, even people who've never purchased anything are on pretty equal terms. I mean, speaking personally, I haven't spent a cent of real-world money in H5, and I've never felt outmatched by the opponent - least not as far as access to vehicles goes.
That story being Master Chief has apparently gone rogue, and you’ll spend most of your time in the game playing as this new guy (identifiable only if you watched the Halo cinematic shorts) chasing him down? No, thank you.
That isn't the story though. It's how the story was advertised, but it's not the story itself.
Again, it's fine to resent the misdirection, but that isn't an inditement on the story itself. Again, take Halo 2 - its story was falsely advertised as well, but it's generally held up as being one of the strongest in the series.
Also, if the actual story of H5 boiled down to "Osiris has to bring in Blue Team," maybe, but we know that isn't all that's going on, ranging from the collapse of 'Madama's Covenant, to the emergence of the Guardians. The apprehension plot is a pretty minor one in the greater scheme of things.