When the US was founded, no country had claimed and controlled as broad a territory (except maybe China, and they used a loose system like in the game) as closely as our federal system created. It could take days or weeks for communications between them. Each US State today is larger than many (most?) countries. So on a matter of scale... There are historical examples of newer scales still requiring some amount of gifting possible between the central and satellite governments.
Not being able to say, 'Hey, I need to buy this building' or 'here's some new objects' other than flat cash is what I see as a major flaw in the game. Because there's no examples of historically stable empires that could not do this. So yes, to me that's immersion-breaking. It's making every government model really the same. The other things seem window-dressing.