"As a keyboard and mouse xbox player, I disagree that the TTK is better. Are you implying that the netcode has some hidden function that if it is a console and is using a controller, the damage is increased or netcode favors the controller-using console player instead of the controller-using PC player or keyboard-and-mouse-using console player?"
YES, exactly this. A console does not have the network overhead that a PC does. Think about what is running on a PC, all the services, the other background processes, drivers, discord, YT or at least a browser opened. It adds to the networking stack. Console is streamlined to do just the game. Therefore, consoles get to the server first. Even if a PC has a faster internet connection (a 5 ping) it does not mean their packets are accepted by the server first. I cannot prove it but I am of the opinion that ALL crossplay games, console gets a networking advantage over PC. I saw this in COD too but no company will admit to it and no developer has talked about it ever!
I will say though, a KB&M using console should have the same network response as a controller using console. That won't matter, but VS a PC, the lower network overhead and faster acceptance/response from the server is noticeable.