Besides the moment-to-moment shooting, what's the one thing that's made Call of Duty the success that it is today? If you ask me, it's the progression. You level up your account, unlocking new guns as you go, which pulls you into the camo grind, all for you to prestige and do it all over again. It's a dopamine rush that worms its way deep into your brain. I still remember the incredibly obnoxious (but admittedly cool) level-up sounds from the original Modern Warfare trilogy era.
Point is, you don't mess with the bones of Call of Duty's finely-tuned progression system. A slice of advice that I wished 2014's Advanced Warfare would have heeded. But instead it threw the progression system out of balance. A sin so heinous, I'd clearly expunged it from my mind at some point in the decade since for my own sanity, only to be reminded of it watching YouTuber Replay Mode's retrospective videos.
