On that same strand, the following games have proven to be quite educational to me:
Caesar III - first city builder I played. Fell in love with the Romans - was well prepared when the basics of Ancient Rome was taught in school.
Pharoah - same deal as above, except Ancient Egypt camw before I had the chance to play.
Age of Empires 2 - this one came with a mini encyclopedia built in about the history of all the units, civilizations, etc. I remember finding this useful when I chose to do a project on French military history for French lessons. I despised French but the project was passed on to the head due to the notable quality and depth (I owe AoK a lot for that one - it was a night before rush job).
Crusader Kings 2 - again, had a little encyclopedia with history on all the historical dynasties in the game. Playing this and reading up on the medieval period & the feudal system is good fun.
Europa Universalis IV - if anything, I didn't know Spain was split between Castile and Aragon until I played this and then looked into it more. Good fun game and great to play alongside a depth dive into the era and the politics of the time.
Graal - the big one. Crappy online Zelda clone. This one provided me the most insight of all: you could build new stuff with it. It had a scripting language, level editor and animation editor. You could take its kbd hack and slash core and turn it into a point and click RPG. This is where I wrote my first lines of code and shaped my career permanently. I owe my employment in part to this game.
And, of course, Civ. Very similar effect as the above historical games.
A great game can stoke your wet ware in many ways. Waste of time? I don't agree.