I agree that a stronger central EU government, more like a federal state would be highly desirable and more efficient in many ways today.
But you are ignoring a ton of stuff here, too. The EU comprises territories that are far more different than the territories of the US. The EU has 24 languages spoken, and its poorest member state has a GDP that is a factor of 9 lower than its richest (excluding Luxembourg). While it would be nice to have strong decision-making, how do you make sure that the decisions are also perceived as fair and democratically justified? Imagine a president who doesn't even speak the native language of the vast majority of people in the country. Would that person be seen as legitimately representing the people? How do you even begin to organize public political discussions in a situation where most people can't read the same newspaper/watch the same content? It's far from obvious that any of this is achievable. It's easy to fantasize about a competent, legitimate central government. But how do you construct it from the pieces given?
The political analogue of the EU might be India rather than the US.
Historically, the EU also comprises the territories that for more than half the time period since the inception of the USA provided all the globally dominant economic and military superpowers, expanding the areas they ruled to the peak of colonialism in 1914 [1]. So the squabbling mess of European powers, barely coordinating under a balance of power system at home, was dramatically successful militarily and economically (at an even more dramatic human cost). Contrast the Quing dynasty, that had a central government. At least some historians I've read argue that maintaining the central government consumed so many resources that it was a major reason for the widening gulf in economic and military might between European power and China during the 19th century.
[1] https://www.nationalgeographic.com/magazine/graphics/1914-co...