To an extent I agree with you, but Halo 4 was so bad that it makes Halo 5 look a lot better than it actually is. Halo 5 is not the best Halo for the simple fact that the map and playlist selection is no where near the level of Bungie Halo games. If the maps are bad that's like half the game. Warzone has four maps (and I personally hate one of them) and considering that Warzone has a bigger population than all of arena combined I think that's a pretty big deal. It was marketed as half of multiplayer. The quality of Arena maps is very poor let alone the lack of diversity in art direction. The design and feel of weapons is pretty bad considering that they are actually a lot more fun to use than they appear. You have gametypes missing and new gametypes that are not working. Breakout is essentially a dead playlist, but we don't get Infection or classic Objective modes that were staples during Halo 2 and Halo 3. Halo 2 and Halo 3 were each #1 for about two years on xbox live so I wouldn't say a game that is consistently outside the top 10 is the best. It wouldn't be constantly getting beat by games that have sold less copies like Rainbow Six: seige. Halo has far more marketing behind it. I know Halo 5 is probably the most profitable Halo since Reach due to REQ packs, but its low sales are a reflection of issues in both single player and mutliplayer. 

I do really like Halo 5, but I would not say it is the best Halo. It is definately worthy of the Halo title though. 

I might be alone in this but the only thing i want new in Halo 6 mp is a double jumping mechanic.

In the single player i have to disagree 1 team is enough actually just one person is enough the 4 player co-op thing they did limits alot their creativity in game design,4 player co-op should have it´s own separate mode like firefight or a better version of spartan ops.

And for the love of GOD bring back split-screen.

I care more about the campaign's gameplay than story. Sue me.

Sometimes the atmosphere matters more than overly complicated arcs and filler characters.

Halo 1-3 may be a simpler story, but I liked it a lot more due to the atmosphere and flow of events. Things in Reach, 4, and 5 feel rushed and less immersed. 

The big issue with Halo 5 was that the campaign felt under-prioritised, especially compared to Halo 4. It was still a fantastic campaign, better in my view than Halo 2 and 3, but below Halo CE, Reach and the highpoint of 4. They did, however, make the greatest MP I have experienced so I hope a fantastic SP (with split screen!!!) makes it into installment 6.

The overarching story of 4, 5 and 6 were already written. Obviously details change and get reworked, but the essnce of 5 and 6 havent changed. Personally I like the more emotional evocation of 4 and 5. 5 had a nice contrast between the more military minded Locke ( Who didnt come through the initial Spartan programe ) and Masterhiefs emotional attachment to his team ( who knew each other from childhood ) and Cortana. Im actually glad the Locke and Chief thing turned out as it did. Because what happened in the last hour of the game was way more important in respect to Chief and Cortana fom the Halo universe perspective.

Cortnana and Chiefs relationship was made massive ay before 343. Particularly in the books. Its fine if you dont like that, but theres much more to the emotion of Masterchief, Cortana and Halsey than Bungie brought out. 343 have chosen to bring out much more about the UNSC, Oni, the Spartan program and the forerunners. All stuff Bungie didnt remotely touch on.

But these things were always there. After all depending on what you know about Halo Cortana is essentially Dr halseys personality in an AI. The only AI she did this with.

But like I said you dont have to lijke this part of Halo. But it existed as a major part of Halo way before 343.

They shouldn't have relied so heavily on Halo's expanded universe for the reclaimer trilogy. I can't keep up with the story and I own every Halo game on every platform they have been released on, hopefully they can bring it together with Halo Wars 2 this year and I can then eat my words.

Halo 4 things were getting difficult to grasp... Halo 5 I had no idea what the hell was going on, I actually had to jump online and do some reading to work out what was happening and build some backstory with the characters that we were introduced.
Halo 4 though I actually enjoyed to a degree.

Halo 3 was the pinnacle in my eyes for the entire franchise story wise, it just brought everything together nicely, I will never forget the horrible cliff-hanger that was in Halo 2... You would think 343 wouldn't repeat the mistakes of the past... But they did.

Or more creative freedom without a locked time-frame before anticipated release. Nothing does more harm to a game then reconstructions on certain features, when the studio suddenly need to do 180s and replace those ideas with half-assed solutions to reach their publishers anticipated launch due for profitable timing.

They had a bookwriter write the fourth installment and then they had the comic book writer write Halo 5... 

All trilogies tend to feel unfinished in the middle act though. The Matrix, Star Wars, Mass Effect, Lord Of The Rings, Halo. I think like most other trilogies the final act will make the 2nd act feel better. Many people now love Halo 2 after 3. Because it fits now.