RaginSam most consoles connect to the internet on wifi. I imagine most desktop PC players connect with ethernet cables. Wifi causes ping time fluctuations which cause network packets to arrive at the destination out of order. For example packet 2 arrives before packet 1. Out of order packets cause time to death to be cut in half.
Battle(non)sense TTD Network Test Video:
https://youtu.be/8Kvj5TZNNJ4?si=_NgPjk63EaY2R2dM&t=936
On your third point. DICE stated they prefer playtesters to use a controller.
Buhl also noted that they prefer playtesters to use controllers so that they can tune that aspect of the shooter.
"We said, 'Here, use the controller,'" said Buhl. "We wanted people to use controllers as the default for their play tests. So, obviously, you might still be playing on PC, but you're playing with a controller. That was a big part of our play testing push, is to get people using controllers."
https://www.pcgamer.com/games/fps/battlefield-6-console-first-interview/
I think it's important for the game to have good controller and mouse support. Unfortunately, I've noticed mouse stutter in Battlefield games since BF1. I really wish DICE would completely eliminate all mouse stutter from the game.
BF6 Mouse Stutter