My thoughts exactly
GP and clamber are the reason for uninspiring map design.
Howso? I mean, what do they do other than promote verticality in a way conducive to the sandbox? I mean, it'd be one thing if we were still talking about the jetpack, which broke the game so heavily that it became a necessary tool since it could get you anywhere from point A to point B with no effort. Clamber helps you make jumps that you're not good enough to crouch jump but punishes you with an animation. There's virtually no clamber jump that you couldn't make by crouch jumping, all it does is make it easier for bad players to navigate these spaces. It also allows for more skilled jumps that incorporate crouch jumping and smart scope - there are a bunch of these on Plaza, for instance, where you can jump from bottom mid to a bridge, or up to a ledge by the plaza proper.
Similarly, ground pound doesn't really effect map design. It's not like things are more vertical because of it - you can get GPs on Block Pit (which plays identically to The Pit) or on Truth (which plays pretty identically to Midship) and so on. It's also incredibly easy to counter because of how easy it is to detect that you're getting ground pounded which is why the Icarus bug was such a huge problem. You gotta charge it up, and you can easily be heard when that happens, and you're functionally defenseless in the air, and if you miss you have to come out of the animation before you can fight back.
Like, can you point to map design decisions that are apparently informed by these mechanics? Are more maps with vertical walkways that you can dive from really a terrible thing? Prisoner, Hang 'Em High, Battle Creek, Chill Out, Ivory Tower, Lockout, Ascension, Headlong, Guardian, The Pit, and so on and so forth all have massive overhead locations that you could ground pound from or clamber to, and I don't know if you've played them in Halo 5, but they play pretty much identically to how they used to. Would Plaza, Coliseum, and Fathom play
that differently if you couldn't ground pound or clamber?
I'm sure that you could take that statement and then just assert "Well if it doesn't change anything, then why not remove it?" It's because it adds interesting mechanics that don't detract from the integrity of the gameplay, which is pretty much the ideal gameplay evolution from sequel to sequel. It's fun and interesting and
isn't negative, which is what everyone wants.