To me the thing that draws me to a 4x game is The complexity of a system but also internal consistency should lead to the ability make informed decisions without knowing the explicit mechanics of the game.

So you can know that empowering industrialzation and urbanization will undermine the landowning class and let you shift power to new leaders in society because it makes sense that as society moves from mostly farming and less land focused economies the less value landowners have a in society. All without you needing to have a formal "Industrialize!" card or phase in the game.

The fact that it's mechanics based also mean you can weird things like industrializing but only your farming only further entrenching your land owning class but developing a middle class of angry tradesmen because the land owners don't support reforms that would empower them at all.

Victoria is a blast