This is exactly true. Now sure the nervous nellies will be all over what outlier things can happen as is typical. In a practical sense the EU does not have the resources to go after (other than perhaps a few test cases for publicity) anything but the juicy or most flagrant cases.
The answer is the same as what extends US law to the entire world. 11 aircraft carriers.
This makes playing nice with the US a diplomatically and economically sensible policy, up to a point. I suspect the US will find it encounters that point increasingly often, partly because the rest of the world is also changing and partly because Trump did so much damage to international relations and the US may never fully recover. The ongoing negotiations about global corporate taxation are a good if rather dull example.