They're all (as is the United States, for that matter) modern mixed economies; capitalism as a dominant economic system proper has been largely abandoned in the developed world in favor of systems which, compared to the then-dominant system named "capitalism" by its critics, systems with comparatively strong redistributive and central regulatory systems, and often a wide array of directly-provided State services, all reforms directed at mitigating the problems for which the critics that named "capitalism" were criticizing it.

Capitalism remains a significant ideology (particularly, surprisingly enough, among the capital-holding class and those who aspirationally associate with that class), and adherents to that ideology often misattribute the success of modern mixed economies compared to other alternatives to capitalism as a success of "capitalism".

Really, the difference between the US and European Social Democracies is between fairly small variations in the details of the structure of a mixed economy -- variations which can have a big practical effect, and are worth discussing, to be sure.