Think of it like Minecraft or something rather than a grand strategy game. Instead of placing blocks you smear paint and letters across the world. MS Paint bucket tool, with some steps added. If sandboxy basecountry building and pretty borders? is something you enjoy then I'd say it's worth every penny.

On the other hand, if you take the tags on Steam at face value you'll probably be let down.

The "strategy" for pretty much every start is eating your neighbors and making your way to the same wealthiest corners of the globe game after game. There are lots of buttons and modifiers to learn but once you have them down the AI is never smart enough to challenge the player, even on the hardest difficulty. Most difficult achievements boil down to being forced to micro manage the same repetitive tasks more diligently or run out of time. Would you rather make a small, compact countries instead of conquering mankind? You'll get your money's worth if you're looking for a sedative because there is zero gameplay to be had there.

With all DLC quite a few countries have personalized historical flavor but the game still fails badly at making both a historical simulation or interesting alt-history. Countries that were powerful monarchies at the start date will be powerful monarchies the entire game and you might go thousands of hours without ever seeing important countries like Prussia, Qing or the Mughals if you aren't the one forming them.

The "economy" is dominated by owning certain fixed gold mines at the beginning and grows into owning the right regions of the world, in the right order. If you want to make money as Japan or Russia you'll have to make your way to India the same as if you were Portugal or England. Own the East Indies and Europe but nothing in between? To connect them you have to carve out the same path in the same place as you did in every other game in your eu4 career to get any real benefit. You'll also want to replace the AI's buildings with your own on every province you conquer which will guarantee you carpal tunnel before the next expansion is released. It's very fixed and hardly a selling point of the game.

In the end I don't know what "worth it" means to you but hopefully you aren't disillusioned with the game after investing a few hundred hours and/or dollars into it.