> provides a much higher social benefit than a single behemoth
In capitalism, companies don't exist to provide a social benefit, that's what the government is for. Companies exist to provide value to the shareholders, that's it. And the US is far better off with those trillion dollar behemoths than without.
The amount of prosperity the US working class sees because of those behemoths puts them at much higher wealth and disposable income than Europeans even after you account for the higher education and healthcare costs.
>even if it doesn't make the magical GDP number go exponential
That "magical GPD number" is also what pays into the welfare services the EU desperately needs. Where do you think the EU will afford that level of welfare if that GPD number will keep stagnating?