I feel like the ability to job hop like this will be in fairly small, concentrated geographic areas. In areas that aren't as concentrated it'll end up being pretty hard to do this.
In the USA, selling yourself like you're the absolute King is ok, but in Germany many people would consider you an arrogant snob that's full of it, if you pretend too hard. They'd also consider someone who job-hops every year to apparently not be able to take responsibility and do their job well, and maybe to be problematic to work with (or they'd not need to run so often).
Switching jobs after 3-4 years is pretty normal, though. It shows that you can keep a job, and if you can show that you also learned something, that's good.
