It is not really about graphics as it is about the scale of a game. Many studios don't even create their own custom engines like they used to to push the most out of hardware and use Unreal Engine. Games take long now because they are much larger in scope and are typically open world. Even the sequel to Breath of the Wild took 6 years and the graphics aren't exactly staggering but the scope of these games have improved a lot which isn't a bad thing. You can get lost in some for dozens of hours. I would imagine studios like From Software even enjoy the ambition of creating games like Elden Ring.