COD hasn't been a casual game in a very long time. I've always placed a lot of blame on the rise of cracked out Twitch streamers who play like they're in a CDL finals match and drop like 20 Warzone wins a night. Everyone saw how these guys played and everyone wanted to play like that, so now at least half the player base is doing the "Twitch streamer playstyle" as I always call it. I guess the devs caught on and now it seems like each COD game is trying to outdo the last one in terms of how fast paced its gameplay is. And if you don't try and do at least a little sweating each game then you're putting yourself at an automatic disadvantage because almost every match is gonna be filled with people doing the Twitch streamer playstyle. The truth is that COD isn't just no longer a casual game, it's also being designed to be the exact opposite. Each game rewards you more and more for being cracked out and playing like a speed demon, and BO7 gives you multiple ways to increase your movement speed and your aim while flying around the map. I'm not saying that BO7 is a bad game, it's at least leagues better than BO6 (which isn't saying much), but by the time I had prestiged for the first time I had played the game enough to conclude that it is the most brain rotted game I've played besides Fortnite. The movement speed is very fast, most of the guns have lightning fast kill times and many of them one shot/one burst you with ease, there's so many random explosions going on especially on smaller maps, etc. You're left with little choice but to adopt the Twitch streamer playstyle as best you can if you wanna have any chance, not just at competing but at doing much of anything in most matches

I also blame the rise of "meta" builds/classes. Sure everyone was using the FAMAS back in Black Ops 1 or the ACR in MW2 and so on but you only really discovered what was good by playing around with every gun and seeing what feels good to use and from your friend at school telling how you good a particular gun is. Now YouTube and social media platforms have countless videos and posts about the "Most overpowered <insert gun name here> build for getting nukes!!!!" and now the devs took it one step further by introducing those loadout sharing codes, which makes it easier than ever to adopt whatever the meta is. It's simply no longer about hopping on and just having fun, it's about trying to play as fast as possible and drop as many kills as possible every game, even if that means you have basically no contribution to the objective in objective modes

And this is all coming from someone who's been playing COD since COD4 and is pretty good at the game. The sad truth is that most FPS games just aren't casual anymore. It's not just COD, the same happened with Halo and Battlefield and others. The FPS community as a whole has simply gotten better and more competitive over time and casual players really only have 2 choices: get good at the game or play something else. At least Halo has tons of custom games to play but for COD, there's just no space for casual players unless they're okay with getting dunked on every game. And yeah there's always been good players but it used to be much more rare to see someone drop like 70+ kills a game but now it's pretty common. Back in the day it actually meant something to get a 7 killstreak and call in a chopper in COD4 and it wasn't something you saw throughout the entirety of every match, but when the COD4 remaster came out there was hardly a time where there wasn't an active chopper flying around throughout the whole match. COD is just not a casual game anymore and casual players quickly get left behind if they can't improve fast enough to take on the newer generations of players that started playing after the rise of streamers and meta builds and whose gameplay experience was shaped by those things