I'll elaborate because I don't shitpost for the sake of shitposting.
I think Halo works best with AR and Pistol starts. These are all around weapons that are competent in any given scenario, allowing the rest of the pick ups to offer you a different gameplay experience for a tradeoff. Halo 5 does this right, and I am glad that the Halo community has embraced Pistols as opposed to Battle Rifles. What Halo 5 then does wrong is make the Pistol a 5 shot kill. This does not punish the movement in the game. The Pistol also only has an effective range of 128 feet. This becomes a problem when people sit across maps and Thrust behind cover. High escapability + the inability to effectively punish players = this games biggest contradiction.
Let's look at the Assault Rifle. It is widely regarded that Halo is based around skill-based gameplay, and therefore precision weapons are said to "take more skill" than automatics. Therefore, the Assault rifle should not be as good as it is for how easy to use, yet it absolutely shreds players, and has an advantage over a player with a Pistol after performing a Spartan Charge. In every other Halo game, the player with the precision weapon (and host, lol) had the upper hand after a melee battle. This is obviously done to give lesser skilled players a fighting chance, but I think it does way too much body damage for how easy it is to use. That's the second contradiction. I do not think the AR should be useless like it has been in previous games, but I was able to nerf its effectiveness in custom settings by increasing damage resistance.
Going back to Thrust, I think this mechanic singlehandedly breaks Halo. First of all, I think one of Halo's strongest and most unique assets as a shooter were its strafe battles. You knew the other player was better than you depending on how good their strafe was. Thrust contextualizes that in a mechanic but doesn't truly add anything to the game that faster lateral movement wouldn't do. You can thrust way faster in Quake by jumping sideways, and I was able to replicate this with custom settings by increasing strafe movement. This is better for Halo because you can shoot while you do it, which makes it inherently offensive. But Thrust is inherently defensive because you cannot shoot while you do it. That breaks room-based maps by allowing people to move into doorway cover quickly; it breaks all the explosions in the game by forcing them to be overpowered to compensate for player escapability; and more importantly, it breaks level design because you are forced to scale maps at least 8 feet higher than normal to prevent players from making vertical jumps. There are two types of interaction in Halo: gun up and gun down. Obviously, your gun is up when you're not using any of the abilities, and it is down or unusable when you are. This means there are two different player states being accounted for in the level design.
Each block in this image represents 8 feet, or about the height of a Sprtan
This is how high the platform on the right had to be in every other Halo game (gun up state) to be inaccessible to the player (unless they had a Jetpack). That ledge is 8 feet taller than the Spartan
This is how high the platform has to be in Halo 5 to be inaccessible to the player. It's three times as high. If I lower that 1 foot, I can make it by Thrust Jumping.
Halo 5 is forced to be vertical not by principle of design, but by lack of any alternative, because otherwise players could just go wherever they wanted.
For example, look at how the Thrust affects the man cannon. While it is cool to change direction off of a man cannon at certain points, consider how broken Narrows CTF would be if you could simply launch the flag across the top of the map. Now consider what a designer has to do if they don't want people choosing wherever they want to go off of a man cannon.
Thrust doesn't operate within a vacuum. When combined with Sprint, Slide and Clamber, the player can scale ridiculous distances.
This is 3 times as far as you can move in every other Halo game.
Clamber on its own is fine, but in conjunction with the rest of the abilities it also fundamentally breaks level design, not just by allowing players to circumvent pathways, but
suggesting that they can go wherever they want. Thus, Halo 5 has bred a new age of Halo players who expect to fly around the map. Clamber could be fixed on its own by shrinking the window that you can perform it, but then people will have to relearn the mechanic and there will be complaints from those who expect to use it vertically instead of "making a jump that you feel like you should have made", which is what 343 said it would be in their first ViDoc.
343 has encouraged this "go everywhere from anywhere" mentality in their level design by delivering free flowing maps, making player movement unpredictable and combat unpunishable, for the aforementioned reasons. This doesn't mean anything in Warzone where it's just a big sandbox of Halo fuckery, but Halo's smaller player counts play best with strict and linear pathing that forces the player to move around the map in a controlled fashion (like most competitive games: CSGO, League of Legends, Overwatch, etc.) which then allows them to use their abilities situationally and not generously. The most ironic contradiction is that they're forcing the game to be competitive through branding and hosting their own pro league. Gaming is inherently competitive, but Halo is not really looking at successful competitive games and learning from them.
Instead of designing strict maps for Halo 5, 343 designed a strict spawn system that is ridiculously predictable. Simply by positioning yourself at the furthest possible point within the respawn window, you can force an enemy player to spawn wherever you want them to every single time. Halo has unfortunately never had a good spawning system (outside of Halo CE's 2v2 spawns), but the current iteration is problematic because of how fast players can traverse a map to collapse on these spawns.
These are just some of the inherent fundamental issues with the game beneath the surface. I dislike other things like the incredibly cluttered sandbox (the DMR and the SAW have absolutely no reason for existing) and continued prominence of double melees in Halo when Halo's melee combat is incredibly shallow due to auto lunge (there was no lunge in Halo CE and you could duck under melees in Halo 2).
Most of these issues are fixable without throwing everything in the game out, but I don't think 343 is willing to do any of it considering that most of these issues are not well understood.