This seems like the core claim, and I don't think it's true? The author references Gallup data on a metric they call "employee engagement", referencing the fact that it's fallen to 31% in the US, but the underlying report (https://www.gallup.com/workplace/349484/state-of-the-global-...) says that that this is the best in the world and the European countries the author is using as a point of comparison have the worst in the world. The idea that people in the US are particularly demoralized as workers, while countries with a strong safety net leave everyone satisfied and loving their bosses, is not consistent with any data I've seen.
(Of course, employee psychology is far from the most important reason why we might want to build a better safety net.)