When we played Warzone, we had 1 friend that was on Xbox. If you want to play with Xbox Players, you HAVE to play with PC Players too! So when we weren't playing with him, we would all turn off crossplay so that we would only play with PS4 Players.
Turning on Crossplay, turns on playing with Both Xbox and PC Players, there is no either/or. We just seemed to find so many questionable kills when we played with Crossplay on (this would involve continuing to watch the person who killed you, then noticing there are a lot of people watching this same person, then noticing them making ridiculous kills and one shots, it was crazy. Sure, there are a lot of cheaters on Consoles, but there are so many more cheating resources and tech on PC and they are very easy to implement.