Bungie understood that changing the core gameplay mechanics would impact the feel/flow of the multiplayer sandbox so significantly, they hardly changed it in each sequel…and look at how successful those games were. They knew what made Halo, Halo. “Don’t fix, what isn’t broken”
I know it’s hard for newer Halo players to understand the effect that sprint and Spartan Abilities have on the game, but that’s most likely because you never experienced the joys of actually mastering and getting good at the original games. I know the Abilities may feel “badass” and give instant gratification, but let me explain:
Clamber = jumps don’t take skill, you can mess up without being punished, less satisfaction than landing a correct crouch jump in the older games
Sprint = maps have to compensate and made bigger, thus you’re getting from point A to point B just as quickly as a smaller map with no sprint (just look at the Midship remake) base movement speed was faster in the older games and you were able to actually shoot whilst moving, sprint does not make you go faster and it limits what you can do
Smart scope = a big part of what made the original games so unique is that you do a lot of firing from the hip, you’re always ready to fight at any moment, scoping everything with smart scope takes away from that, this aint COD
Thrusters = limits the cabities of strafing, it can take someone months of playing to master the strafe in the OG games, but in H5 you simply press 1 button, anyone can do that and it gives the player an easy “get out of jail” card for bad positioning
Ground Pound/Spartan Charge = just plain annoying and not much counter play for the opposing player, don’t get how you can push Halo 5 so hard as a competitive game with gimmicks such as this
The list goes on…
Please just try to improve on what was already there, without having to completely change it.
Innovate through map design, gametypes, weapons, forge capabilities, triversal etc.
Instead of trying to be the next COD or Titanfall 3, just try to be Halo. Just look at what good going back to their roots did for franchises such as Doom 

