Yeah I’ve spent a significant amount of time just building a little civilization in the ruins.
They introduce you to it in the story quests, it’s great to explore after you run out of other things to do. It’s a great way to make money in game too.
There are a lot of mods that expand what you can do with building. I recommend a mod that removes the build limit. My main settlement is probably 3 or 4x the default build limit.
Fallout 4 is seriously underrated. The only game I’ve spent more time on is Skyrim.