Civ modding is dead after Civ 4 because starting from Civ 5 there is no .dll access which means unlikely there is going to be anything complex enough from modding scene outside of number adjustment and the occasion new units or the likes.
Actually, Civ5's dll is available here. There is, reportedly, a number of total conversion mods for Civ5, but I'm not aware of any that ever approached FFH in popularity. Not that I ever held much interest in 5's modding scene, as I played it on release and got really burned by how shitty it was. Civ6 was a move in the right direction IMO, but then they dropped the ball on the expansions and never released the dll source so...