To make it short, i'm pretty sure the problem is on the crossplatform netcode.
I won't talk before season 2, game was quite a mess...
But in season 2, even if hit reg wasn't fantastic, the game was going on the good direction.
Since season 3 it is going down again. Weird deaths after reaching cover, feeling one shot killed at medium range (50-80m) by some weapons that shouldn't, etc, etc. Players feel cheated by the game too many times because of the responses they have on their screen.
My PC is not especially young... I7 7700 and GTX1070 for 1080p all low it works. And i have great internet, fiber optic no packet loss and ping at 12.
I'm sure i have no internet problem, and i see people with more advanced hardware with the same issue. And the same issue affects consoles too... It's not hardware related.
I'm seing a huge increase in the return of console vs PC war, how many "stop crossplatform" or "aim assist is broken from PC receiving end" subjects in this forum ?
We didn't had those problems in BF1 and BFV. Dice state the aim assist is at the same level as previous. Soo why players feel cheated ? And worse, both sides (controlers and M&K) feel cheated.
With a friend we laugh about the "Xbox cheaters" since season 3... Of course we don't believe they are cheating, but from the receiving end, the shots are miraculous and it seems to be insta death on some occasions (it's not consistent fortunatly). If Xbox players feel the same from PC players i understand the hate. Curiously i have far less issues with Playstation when killed, this increase my suspicions.
I think all those problems of TTK vs TTD, aim assist "too powerfull", "all PC are cheaters cut the crossplay", etc, etc, comes from the crossplatform netcode.
All players who played with crossplatform off are saying the same, the game is really better. I did it with friends (hard on PC most of the time matchmaking don't find a game, congrats Dice). But when we succeded, waow, it's night and day.
Try it by yourself you'll notice the difference with your first shoots.
I'm not a programmer, but i'm pretty sure this is where devs should look to solve all those problems.