Throughout my time playing the game in the last 13 years, the difficulty of the game was always based on where you were in the world. For instance, if you wanted a peaceful playthrough, you would settle in a calm area without hostiles. For challenging times, you would settle down in a haunting or terrifying biome near a necromancer tower. It makes sense right?
The way the difficulty setting used to work was more attuned to the realism of world, because the environment could explain why things were happening.
But it doesn't anymore with the Enemies "Off"/"Normal"/"Hard" switch that you see when embarking. The game doesn't put as much emphasis on world interaction now that you can be in the worst evil biome there is, and have nothing bad ever happen at your location for simply having the option to turn the enemies "Off" for that run. You're not supposed to have any direct control over an already established world and the enemies that live in it, yet that one new button does. It's not a parley, nor asking for war or peace with creatures--it's a 4th wall button.
That makes it so that evil creatures are forced to play out of character, especially necromancers, they would all refuse to pay heed on a settlement that was established near them. Maybe they will still try, but the fort would be considered invisible (?) to them. Not sure what the dwarves would make of that odd behaviour.
Between the time a fort that's invisible to the outside world starts existing, and the time it becomes visible as soon as it is abandoned (or retired), a hypothetical perfect Legends mode would have trouble figuring out what the hell just happened there.
It's the environment that should always have a say in how it wants to be encountered as per the laws of the world works. It's why I would like to request for the difficulty setting to go back to how it used to be--being purely based on where you are in the world. Some places are just more dangerous than others, and for a reason.