People's response times go to shit as they get older. Games without some kind of affordances for that (or just difficulty settings) are much, much harder for older folks than they were intended to be.
The tradeoffs are much less clear for prose. That said, outside of fiction writers should absolutely be thinking about accessibility, and should pay attention that they are writing in a way that can be understood by their intended audience (which may include people with cognitive impairment).
Further, if someone who has difficulty with Crime and Punishment wants to read it, there are abridged versions, audiobooks, dramatizations, and other ways to enjoy it.
And if you really want to play Dark Souls and can't be bothered with all the tools the game gives you that make it easier, you can mod it or use cheat engine.