Buildings seen in cities

When I look to cities in Civ5 it seems I am looking for the same city when they are with population and eras equal, and I wanted that the buildings were seen on cities. That would make the maps larger. The cities will be different depending by civ, tiles, climate, etc.
The spys (like CivRev), units and bombs can destroy buildings.

I think that would be a bad mechanic because players would then be able to se nearly everyting that a player is doing
and on top of that u could write a Eui that warns you if a player if no new building showed up in a city for a while that that guy is building army
but having acces to the information when what building finishes alwes u to write a eui that can more or less tell u not ondly the ammount of units the enemy has, it also alowes u to know what unit's they probobly have since u more or less know the production of the city because of the buildings built in the past and the population size and productionbuildings in the city

Thanks for the opinion.
I also think that, and for resolve that the fog of war would extend to cities, and the buildings only would be seen when you enter a city by war or with Satellites