Beat around the bush all you want, the success of a country is mostly measured in economic, political and military power and in EU4, these all equate to more land and base tax. This expansion promised an alternative strategic route (much like in civilization games), but doesnt really succeed in doing so. Sure, EU4 is a sandbox game and you can set your own goals and do whatever, but in terms of advancing your country and influence, we still have a clearly superior way (expanding your territory through diplo-annex/PU/conquest) and an inferior way (improving existing territory), even with the absurly over-nerfed coring and annexation costs.