Controllers are anathema to me. In 15 years at least I went from completely hopeless to managing to finish some games that I really really wanted to play. But only on easiest or story mode. And it was still harder for me, than any game ever was with moues+kb, on the hardest difficulty.
I think maybe some of it has to do with what you grew up on. Like I didn't grow up playing PC games, but rather console games. Our computers growing up were barely functional and were able to be used for pretty much Compton's Encyclopedia, some internet, and word processing. I do remember Wolfenstein 3D being the first FPS I played and that was on the PC, but beyond that I always had a console until I started building my own PCs around the age of 14 or 15. In any case everyone plays with what feels best of course but controllers are insanely helpful in a lot of games. I mean I would be curious if you went to play Ace Combat 7 whether you would feel the same about KB+M. I couldn't play an arcade flight shooter with a keyboard, or racing games (minus an actual wheel), or most 3rd person games like Grand Theft Auto which is perfect for controller being that you switch from running, flying, and driving fast.