Eurozone leadership will never do that, because of national egoisms. Just look at how Airbus builds its airplanes, because everybody wants a slice, so they fly each airplane body halfway across the continent and back... And Airbus is just 4 nations (FR, DE, ES, UK). Collaboration across all of the Eurozone or all of the EU would be a mess of ITER-like proportions.
If one was designing a European aircraft manufacturer from the ground up one would not choose the Airbus model… but that’s not what happened. They were all going to require state subsidy, presumably the total subsidy is less than if each state were subsidising their own aircraft manufacturer to compete with each other. And if they had settled on one location and the other sites had shut down you and I well know the governments would just be subsidising jobs in some other industry.
“National egoisms” is a nebulous phrase. The fact is that they would have been punished by their political systems. The governments handed out the subsidies that were necessary to not be punished. That’s democracy.
Even with privatisation in the 90s and many on the left disputing this, Germany is still considered a social market economy ("Soziale Marktwirtschaft").
