It may be surprising cause the base game was very meh, but Fallout 4 has a huge modding community. When you take a look at mods that were released, F4 has a lot of high quality stuff relased by fans. Some mods are pretty much proper expansions in terms of scope. Things like America Rising adding a new faction storyline with Enclave, The Bleachers series expanding Diamond City, SimSettlements which expanded building features and added proper story attached to it. There is also a whole remake of Point Lookout, F3, FNV and even Fallout 76 map being remade on this engine and upcoming London mod which scopewise looks like a standalone game
