It's worth noting that there's inherent value in having additional points in your capital specifically, and concentrated into specific provinces more generally. Additionally, any country that can move its capital for free is going to be able to use it more frequently; Ethiopia is the obvious one, but many countries will move their capital on formation, for events, or upon mission completion as well. I'm most of the way through the Mewar Never Changes achievement, and there's about three different missions that relocate your capital to different places in their mission tree.
Firstly, there's the obvious- govcap. Any development in your capital is much cheaper than anywhere else in your state. The more you can extract, the cheaper it'll be.
Secondly, there's a lot of opportunity cost in grabbing new provinces. Taking highly-developed capital provinces is always going to be expensive, and anything you take is going to have years of startup time in rebellions, high autonomy and other factors such as religious conversion before it's actually a productive part of your nation. Shoving dev in your capital, meanwhile, is just an instant boost that causes you precisely zero problems, with very few exceptions.
Thirdly, and perhaps most importantly, many extremely good modifiers are to a single province only! Any resource you invest in a high-dev, well-placed capital is going to get massively better returns than it would in any other province. To summarise a few possibilities-
-Trade goods are perhaps the most obvious one, and manifest in a variety of ways. There's the direct price, of course. Then there's the per-province trade good modifier, and the 'trading in' bonuses on top. For example, cocoa has over +150% trade good value at the end of the game compared to grain, and additionally adds +10% manpower to your province, with an extra +5% manpower recovery speed if you dominate the trade enough for Trading In to happen.
-Fort defence is per-province, and you get +1 in your capital, so it's a lot easier and more worthwhile to defend a fortified capital than anywhere else you have.
-Buildings are a flat cost regardless of development, so the better the province you put them in, the better they are. And they often combo, too- spending 100 gold for +50% production efficiency is much better on a 40-dev capital with Cloves than a 20-dev province with fish.
-If you haven't tried the Expand Infrastructure button, give it a go! It's currently bugged to delete all the bonuses if you make a new nation, but you can buff pretty much every single part of a province if you click it, at the cost of govcap. If it's in your capital province, though, you can mostly mitigate that govcap cost! Later in the game you can centralise the state to reduce its gov cost even further.
A lot of these bonuses are most useful in the early game- when buildings are still expensive, your capital fort is a vital part of your war defence, rebels are a significant threat, and institutions are basically never easily-available unless you dev them or you're in Europe. Additionally, many of these bonuses are better for 'comfy' playthroughs that expand more slowly for slow-and-steady progress instead of fighting an endless number of rebels; it's pretty useful in the HRE. So while it's often very situational if you're trying to play meta, certain playthroughs and countries are going to make much better use of the button.
Firstly, there's the obvious- govcap. Any development in your capital is much cheaper than anywhere else in your state. The more you can extract, the cheaper it'll be.
Secondly, there's a lot of opportunity cost in grabbing new provinces. Taking highly-developed capital provinces is always going to be expensive, and anything you take is going to have years of startup time in rebellions, high autonomy and other factors such as religious conversion before it's actually a productive part of your nation. Shoving dev in your capital, meanwhile, is just an instant boost that causes you precisely zero problems, with very few exceptions.
Thirdly, and perhaps most importantly, many extremely good modifiers are to a single province only! Any resource you invest in a high-dev, well-placed capital is going to get massively better returns than it would in any other province. To summarise a few possibilities-
-Trade goods are perhaps the most obvious one, and manifest in a variety of ways. There's the direct price, of course. Then there's the per-province trade good modifier, and the 'trading in' bonuses on top. For example, cocoa has over +150% trade good value at the end of the game compared to grain, and additionally adds +10% manpower to your province, with an extra +5% manpower recovery speed if you dominate the trade enough for Trading In to happen.
-Fort defence is per-province, and you get +1 in your capital, so it's a lot easier and more worthwhile to defend a fortified capital than anywhere else you have.
-Buildings are a flat cost regardless of development, so the better the province you put them in, the better they are. And they often combo, too- spending 100 gold for +50% production efficiency is much better on a 40-dev capital with Cloves than a 20-dev province with fish.
-If you haven't tried the Expand Infrastructure button, give it a go! It's currently bugged to delete all the bonuses if you make a new nation, but you can buff pretty much every single part of a province if you click it, at the cost of govcap. If it's in your capital province, though, you can mostly mitigate that govcap cost! Later in the game you can centralise the state to reduce its gov cost even further.
A lot of these bonuses are most useful in the early game- when buildings are still expensive, your capital fort is a vital part of your war defence, rebels are a significant threat, and institutions are basically never easily-available unless you dev them or you're in Europe. Additionally, many of these bonuses are better for 'comfy' playthroughs that expand more slowly for slow-and-steady progress instead of fighting an endless number of rebels; it's pretty useful in the HRE. So while it's often very situational if you're trying to play meta, certain playthroughs and countries are going to make much better use of the button.
