Because.sprint, clamber and glide are great movement options as is grappling hook
Sprint - Can't shoot, elongates maps for a net positive of zero, is a press 'X' to escape mechanic.
Slide - breaks movement, gives small hitbox advantage without speed penalty. Makes crouch unbalanced.
Clamber - can't shoot. Can't move vertaically without having to look in a specific direction instead of being able to jump in any direction while shooting
Grapple for movement. Can't shoot. is just another press 'X' to escape mechanic. Breaks map design and flow.
Still no evidence provided that Halo needs that garbage that straight up breaks it's gameplay.