EU4 is an okay game about conquering ridiculously large swathes of the world, but it's sorely lacking in the historical simulationist elements that I think make other Paradox games so compelling. There's precious little actually going on inside your country that's not just buttons you have to remember to press every once in a while, and events that could be really interesting to try and model, like the Protestant Reformation, tend to be flattened into really dull "define your playstyle for lategame" mechanisms that would be much more fitting in something like Civilization where distinct playstyles exist as a concept.

There's some ideas in there that are compelling, and in particular the (notoriously incomprehensible) trade system seems set up to organically encourage colonial competition along loosely historical lines, but most of the game isn't designed along that philosophy; a lot of things that seem like they should happen organically via game systems, like the 80 Years' War, just don't, and have to be forced out through scripted events. It comes away feeling weird and gamey as a result.

I have a lot of hours in this game--my "completed" status on this game is true, incidentally, I've played multiple full 1444-1821 campaigns (Netherlands and England, off the top of my head)--but it's ultimately just kind of thin and dissatisfying once the illusion falls away. Add to that the atrocious DLC structure, which is maybe Paradox's worst, and I'd point newcomers to basically any other title in the franchise.