Depends on game, considering Sekiro was brought up I play all DkS games with a Nintendo Pro controller and serves me well. I also PvP in those games so would know if I was at a disadvantage.
RTS, FPS, and a few other genres benefit from M&K but not everything in my personal opinion.
Then again if someone only ever plays with a M&K/ pad it may be more natural to others. Personally could never play a Resident Evil or Evil Within well with a M&K excluding Resi7 and FP mode in TEW games.
I always use controllers unless I play a MMO or Strategy Game. It is what i grew up on. One thing I do notice is when I use a Controller when I record for my youtube channel (https://www.youtube.com/channel/UCcjK6Jk-KSTf-EGn_jVyOhQ) is that you can hear the controllers buttons very easy with the microphone I use.