The goal of reclaiming territory in Fallout 4 is a noble one, and the concept of building safe and livable settlements can make you feel like you're having a positive impact on the world. On the other hand, building multiple settlements is a bit of a pain in the ass since you—and you alone—are responsible for the placement of every single wall, window, door, and stick of furniture. Plus, NPCs arriving at your settlements need to pointed at the specific stalk of corn you want them to harvest and the specific bed you want them to sleep in.
This may be fine if you're into micromanagement, but there's something to be said for a town that takes care of itself and for citizens who take matters into their own hands. That's the idea behind Sim Settlements, a Fallout 4 mod that turns settlements into a SimCity/Cities: Skylines type experience.
Rather than placing foundations, building walls, attaching roofs and doors, and placing every last bit of furniture, you instead just place zones in your settlement for residential housing, commercial and industrial areas, and farming plots. If it's a residential zone, for example, a 'For Rent' sign will appear, and eventually a settler will wander over, claim the plot, and get to work. They'll erect a home, complete with a bed and other furniture, and move in. They'll plant crops or open shops. Their buildings will even level up if the health of your settlement is high enough, so when you return after an adventure or two you may see bigger buildings where once stood humble shacks.
I'm sure this isn't the experience every player wants—many people enjoy hours of building and arranging every last detail of their settlements. I do think it's an interesting take on the settlement system, though, one that requires less direct management from the player while at the same time providing more realism and immersion. Instead of returning to find a settlement exactly how you left it—except for a few new settlers standing around waiting to be assigned to something—you can see actual progress as the settlement you founded grows and thrives. It makes sense, too: while you're off killing mutants and robots, why wouldn't an NPC build a second story onto his home?
A lot of consideration has been put into Sim Settlements, from the randomization of the houses themselves—you'll probably never see two that look exactly the same—right down to the clutter you'll find when a home is built and a settler has moved in. For instance, if a settler has a table they eat their meals at, you may see dishes and bottles on that table, but at other times those items may be put away, as if the citizen tidied up after themselves. It sounds like a neat system that makes settlements feel like real, lived-in places.
There's a lot to it, and a series of videos from the modder, kinggath, does a good job at explaining the various features, and what may be added in the future. It's also highly customizable with a number of features that can be turned on or off. Sim Settlements is still a work in progress, but you can find the latest build here at Nexus Mods.