Now you could micromanage resource production and trading. However, trading works on monthly ticks, and a game of EU5 spans 500 years, 6,000 months, and you would have to optimize trade on every market you are present in. So the overwhelming majority of EU5 players just automates trading. Manual trading is slightly better, but experiments suggest the difference isn't huge, about 10% more trade income for manual trading. Given the huge effort manual trading would involve for any medium sized or large country, that just isn't feasible. And even if you switch off automated trading, you still have burghers pops that trade, so you never control all of the trade in your country.

Nor do you control all production. In patch 1.1 a major change to the economy resulted in the estates earning a lot more money, and they use that money to build buildings, resource gathering operations, and roads, just like the player does. There are also "mass build" and "mass upgrade" buttons, so when you replace your scriptorium technology by printing workshop technology, you don't have to upgrade a hundred buildings manually.

In my Byzantine Empire run, in over 3 centuries I haven't done a single manual trade. While I do construct resource gathering operations and buildings, I mostly do so using the mass build and upgrade buttons, as everything else would be too fiddly. And I simply ignore the notification saying that some of my pops have unfulfilled resource needs: It turns out that building and trading by the burghers is enough to fulfill all reasonable needs. The unfulfilled resource needs that I am notified about are things like tea, where the global production is just a fraction of the global population needs, and as each market first fulfills its need before exporting, tea never actually makes its way from China to Europe. It also turns out that pops having unfulfilled needs for exotic goods doesn't meaningfully impact your country.

So when I look at the whole system of population needs, resource gathering and production, trading, and everything around it, I see a hugely intricate and complicated system that I am only marginally interacting with. That part of the game mostly just plays itself, without my input or attention needed. I would need to play a very small country very slowly to have a major impact on my economy myself.

And all that isn't that much fun. At some point my Byzantine Empire expanded covered the whole area from the Balkans to the depths of Anatolia, and I didn't want to expand anymore. I took Rome for fun, as there are events linked to controlling it. But I am already the greatest power in Europe by far, and if I wanted to become the greatest power in the world I would need to expand all the way to China, which doesn't seem worth it. So I am mostly running an automated game at highest speed, waiting for stuff to happen.

Only, the stuff that is happening in the later half of the game isn't much fun either, because it is the same for every country: The age of absolutism has your estates getting uppity, so you need to manage that internal strife. The age of revolutions expands that to you having to fight your vassals and colonies to keep them under control. It is all highly scripted, doesn't much take your current real situation into account, and is mostly annoying. It is a bit like those city building games where at some point a volcano erupts in the middle of your city, just to provide a challenge to a game that has gone stale. I'll probably stop my Byzantine Empire run soon, before reaching the end date.

I understand why EU5 needs automated systems, as forcing players to do everything manually for a large empire would be even worse. Events in EU5 are mostly not much fun. While there are a few country specific events, over the course of a long game the most events you deal with are the generic ones, sometimes repeatedly. And with the tech tree also being mostly the same for every country, the overall experience of different countries converges to something very similar in the second half of the game, regardless of whether you started as a large country, or started small and then expanded.

So I think I'll stop playing EU5 for a while again now. My next run, somewhat surprisingly, will probably be the Byzantine Empire again, but in a month or so. Because that was the purpose of my current run: A practical test on EU5's new DLC policy. The first DLC will come soon, and it will be mostly country specific added content for the Byzantine Empire. The question is how playing the Byzantine Empire differs between before that DLC and after, which then might answer the question in how far those DLCs are worth buying.