Fallout 76: Player CAMPs are very important to the game, as they contain essential equipment, and defending them is important. Still not a lot to the layout in terms of gameplay. Some people (not me -- I'm in the "floating platform" crowd) really enjoy doing realistic and aesthetic CAMPs, and it's a way to help put a very limited form of player-driven content creation into a form where everyone can easily enjoy it. Player vending machines, scrapboxes, respec locations, and workbenches (to create scrapping locations for overloaded players) create a reason for other players to visit and see them. Extremely limited automated production of certain resources -- if you want some very specific builds, like Nuka-Cola-based weaponry, automated production might be useful, but in general, it's not worth your time.
There are player Shelters as well, "underground" or otherwise off-the-main-map mini maps that players can own and build freely in; there are entered from various entrances created in a player CAMP. I think that this was intended to leverage a survival aspect of Fallout 76 that was originally intended to be a lot more important -- radstorms, and needing to seek shelter. These are so infrequent and weak, though, that by the time one gets to Shelters, they're essentially ignorable. Nothing in a Shelter can be attacked by raiders, but automated production does not work in a Shelter.
With a subscription, there are placeable Tents that can be put on the map in places not one's CAMP. These provide a resting, scrapbox, and scrapping location that can exist anywhere. Helpful QoL to stick near boss fight locations.
Bethesda sells cosmetic items, if you like that sort of thing (which based on EA's sales of items for The Sims, I assume some people very much do like). Not very much potential for modding here, due to it being a multiplayer game with the servers run by Bethesda, so unless Bethesda gets and decides to plunge a lot of money into it, vanilla Fallout 76 is probably about as much as there's going to be.