Not Ottomans or city state quest. I didn't advance an era, although I may have discovered a tech.
I think my point is not so much why this happens, so much as should this happen? It is difficult to determine, and the mechanics are obtuse. Of course you may disagree, but I would rather see instant yields cut back.
It is WAD. Gazebo loves instant bonuses for a handful of reasons.
First and foremost, they do not scale out of control.
Second, they do not contribute to happiness. So civs that rely on instant bonuses may get the yields, but the population feel insecure, the same as you.
Third, this is my guess, they add some unpredictability, which makes it harder for civs that rely on instant yields to time their actions.
Civs that rely on instant production yields, you may ask? Warmonger, religious and diplomatic related. You never know when you'll get yields from killing enough units, spreading your religion or befriending a city state.
We complained a while ago about those instant yields which were not shown in the UI, they just appeared for a few seconds over the cities. So G went and modified the whole UI so we could have all those yields explained every turn, grouped by type. You did complete a city state quest? It will say so, and how many yields the CS gave in reward in which city.
If you like timing, then don't get too involved with city states, and focus on great people instead, they are more reliable. By the way, if you use Improved City View, it's a piece of cake to control your specialists.
