Mouse and keyboard on a 30fps game is completely and utterly worthless and a disadvantage if anything. While controller using a cumbersome and inaccurate method of aiming, the thumbstick, it has aim assist to help with that. The mouse has no aim assist but it is completely precise, you can point and click wherever you want. However, you completely lose that sense of precision when you are playing on a slideshow with the input delay that comes along with that. Not to mention you would be playing with console recoil which is very harsh in this game. At 60 fps, which is what I play on pc since I only have a 60hz monitor, it is very smooth. Input delay is not noticeable whatsoever and aiming with a mouse is a very satisfying experience. I tried playing on mouse and keyboard capped at 30 fps one time just to see what it would be like playing MNK on console and it was god awful. It absolutely is not advantageous at all.

If you’re hunching over while using m&k you need to work on your posture.

Paddles on a controller also provide a noticible advantage to a default controller. These third party controllers cost just as much as a xim and M&K so both are equally accessible. If you're going to condem M&K then you have to condem third party controllers as well. There's no reason to spend the same amount of money for a lesser product just to have the moral high ground. If a good (and equally affordable) M&K adapter existed when I played on console I absolutely would have used it. M&K support is coming to all consoles and many new games in the coming years anyway, if you stay on a controller you can plan to get left behind in fps pvp.

They won't ban them. People who use m&k on console are just trash they want an advantage over controllers but don't want to play better players on PC with m&k.

Using a mouse on console is nothing like using a mouse on pc. It's more likely these players are just very good.