I'd say it has something to do with the name of the game
Europe isn't OP at the start, they just have a better tech group. In fact all the arab states have higher tech at the start giving them an advantage. In the EU3 timeframe the only serious threat to Europe was Ottoman empire
It should be noted that the difference in tech at the start of the game, a mere two levels, will fade away in about two decades, meaning Europe's rise takes place between roughly 1430-50 in EU3. That's nearly a century too early if we're primarily looking at land technology. It doesn't matter whether the game is focused on Europe or not, it's still misrepresenting them.