Gaming

The problem with difficulties is that it's much more difficult to design an AI system which you can tweak and make it smarter or dumber as opposed to just increasing damage and health values, so devs will just implement the best AI they can and leave difficulties as afterthought.

After playing a lot of games that don't even have difficulty settings, I've started to believe in the idea that difficulty selection is just outdated game design and that having a single difficulty but optional areas/content that is more difficult is the way to do it. OSRS is one of my favorite examples - everyone plays the same game and going through levelling or whatever isn't mechanically demanding. However, there are bosses and challenges (like Theatre of Blood which is an end-game raid or Inferno which is an end-game challenge) that are incredibly challenging and require weeks if not months of attempts to master and finally beat, but also are perfectly skippable and most casual players don't even bother with them.