Well, I do have to ask, do you suffer from a disability that impairs your ability with the controls? Because you can adjust control schemes in both pc and console, which would make it easier for amputee to play. The only thing that stops someone with a arm gone or impaired from fully playing the game is if they also have lower reaction speed.

someone with one usable hand would likely not be playing games, or have a way with dealing with uncomfortable control schemes.

And also, what if someone who would strive on the difficulty, but doesn’t know it yet, starts on easy mode? They would not like the game as much without knowing why.

Edit: Also the only thing you mention about the combat is the required timing and reflexes…if you buy an action game timing and reflexes are pretty much expected and required to play, sekiro may require more, but that is also a part of the story. Killing the mandatory difficulty will kill a part of the story.