As someone who's put in about 1000 hours across all three Dark Souls games, here's my insight on challenge: those games aren't actually all that difficult. The only reason people uphold them as absurdly difficult is because of memes and unskilled journalists.
When I was new to the games back in 2014, I used save editors to cheat and give myself higher stats and upgrades, because I was irritated and didn't entirely know how to face certain challenges. But by the end of the year, I was able to take those training wheels off and realize I never needed them to begin with.
What I came to learn is that Dark Souls's main difficulty is because it's an entirely unique genre compared to most action-adventure games. And just like any genre that's new to you, there's a learning curve. For example, I've spent thousands of hours of my life playing first-person shooters. Hand me a new shooter, I'll pick it up pretty quickly, just because I'm so experienced at it.
FromSoftware's games had been pretty niche until Dark Souls's explosive popularity, so not many people were familiar with the genre. Combine that with its minimal exposition about game mechanics, open-ended world design, scarcity of bonfire checkpoints, and everyone from journalists to casual gamers only saying how the game is super difficult, and you'll get the impression that these games are just about "**** you" difficulty that is designed to be unfair, when that's not the case. Especially for casual gamers who like to pick up a game, play it through once, say they beat it, and then never touch it again.
Very little challenge in the Dark Souls games are unfair. The first game is the roughest, with moments like the Capra Demon and the Anor Londo archers, along with certain poorly executed mechanics like curse, but otherwise there are a variety of strategies to overcome any area or enemy. Even the notorious parts and areas like Blighttown aren't too terrible once you understand what it is that makes them challenging and how to face it. Sometimes the game will spring traps meant to catch you on your first visit, but even those aren't always unavoidable or fatal.
I actually sometimes played Dark Souls games to relax, since they weren't fast-paced multiplayer games and I had come to understand their difficulty and mechanics. Most deaths in those games come from the player being punished for huge, obvious mistakes, not because the challenge is so overwhelming you have to be busting your butt in each moment of combat or else "YOU DIED".
By the time Dark Souls III came around, and especially when its DLC's were released, I was able to beat some of the areas and bosses without dying a single time, with no cheating or manipulation whatsoever. I'd just become so practiced at the games that I often understood how to react to and face the challenges smartly, even if the areas and enemies were unfamiliar.
It's the same with platformers. My brother, who's hardly played platformers, gets his ass handed to him by Shovel Knight, and for a while, Hollow Knight. But then recently he returned to Hollow Knight, was more familiar with the challenge and the genre, and has been playing it nonstop and considers it one of his all-time favorite games after initially hating it.
Some games do have unfair difficulty. A lot of older NES-era games were like that, because video games were relatively new, and game design wasn't entirely understood yet. NES games like Castlevania would do things like make you fight two axe-throwing knights who each take 9 hits to kill while also having a neverending stream of Medusa heads flying around the room while you have very few defensive options and no way to recover health. That's just straight up unfair and poorly designed.
But very few games today that are inherently difficult are unfair by design. Their difficulty is just because it takes time and practice to understand and learn the game. And nowadays when many people don't seek to play games more than once, including YouTubers or streamers who may or may not be too skilled at games to begin with, it's easy to get the wrong impression from difficult games.