The Forgotten City has “overwhelmingly positive” reviews on Steam with many people praising it for its Bethesda-like systems, so I’m not sure what you mean. Maybe you felt it wasn’t enough like Skyrim and disliked it for that, but clearly you don’t speak for others.
Also, no other Skyrim quest mod, out of the near 2 thousand quest mods for the game, had a full game built off of them. So while that does happen sometimes (ie Dayz), it’s exceedingly rare and far from some sort of “tradition” as you put it. If anything that was far more common a decade or two ago than it is now. The original Star Wars Battlefront mod was quite a long time ago after all.
And no I’m not mad, I’m just confused as to how you could think Skyrim has only bug fixes, UI, and graphics mods, when in reality it has nearly 7x the amount of mods that Morrowind has and is the primary example of a thriving modding scene. Idk if you just spouted that out without knowing, or what.