You can trace some of the features in Civilization VI, such as Civics and Religion, to its origins in Civilization IV. Civics allow you to specialize your civilization's output such as labor or military might, and Religion was another method of spreading your culture to rival cities, which was helpful if you wanted to win via Culture points. However, those who prefer warfare can find some unique advantages within the game as well. For example, one tile on the map has the ability to house a plethora of units, which made it easy to lay siege on a rival city. It was highly exploited to the point that its sequel, Civilization V, removed the feature entirely to limit the number of units available for your war campaign.
Aside from the base game, there are two expansions that add more content to the game, such as vassal states, new civilizations, random events, and espionage. If that's not enough for you, there are many mods available that ushers in new gameplay changes, civilizations, or scenarios. All this content fills the need for "just one more turn" to the brim and then some.