Crossplay allows PC players to cheat without consequence.
Cheats are going to cheat, I don't think the cheating is as widespread as you claim.
Can you quick scope in combat? No, snipers train to take one accurate shot, not 7 to 8 shots in 3 seconds by lifting the scope. It's nonsense and ruins the gameplay.
I play on PC, I have a friend on PlayStation, I'm not particularly good at using sniper rifles, he plays sniper like he is on God mode. He can easily beat me to get to ads and take a shot, it's all about the setup, practice, and muscle memory. We have played many a game of free for all together, either just the 2 of us or a small group, snipers only, and he wins every time, he can even outgun players with LMGs, SMGs, and ARs.
As for Quickscope in combat, maybe you're playing the wrong game, I don't think people buy CoD games for realism, games that work like real combat are not fun, people don't jump around corners and prance around jumping and sliding all over the place. Soldiers tend to move in formation, communicate efficiently, support each other, and they don't respawn a few seconds after getting taken out.
I was in the game and when you get raped by the same idiot over and over it shows the number of times you've been killed by that person in the cut screen. When you see 20 plus deaths to aircraft in less than five minutes in a multiplayer match ..... there is a problem. Warzone is unplayable.
I would like to see a video of that.
I just Google Plunder and respawn times and found
this website, where it states this about plunder:
A very important aspect for this mode is that respawn is fully enabled. If you die, there’s a 15 second timer, and once that’s up, you can sent back to redeploy onto the map to get back into the action.
So I looked that up because I like to deal with facts and not exaggerations, 20 respawns would take 20*15 seconds which is 300 seconds, and 300/60 is 5, so that's either some highly effective cheat that not only kills you the first time, but accurately times and places the next airstrike to hit you the moment you get back into the game.
Now if you're not playing Plunder, then how are you able to get back into the game 20 times?
We have had many a conversation and even full-blown rants about 'PC Cheats' on these forums, but as I said, I don't think it is as widespread as people make out, most cheats play to win, and they are don't target individual players, they target all players and trample over anyone that gets in the way so that they can achieve their win and build their stats.
You make it sound like the cheats you have come across are targeting you specifically, and that can't be right, plus for you to get killed 20 times in a single game by the same player suggests that you're making yourself a far too easy target.