The difference is that US Billionaires are doing it without being elected or officially assuming power to do so. In Europe it is important to keep it official as you can just burn their palaces and run them through the guillotine, which even feels wrong saying it in open on US based forum but that's how it has been since many many generations. Europe has seen so many January 6th over they years.
You know how they say that USA is a very new country and that even some pub in Europe can have longer history? Well, that's true but it doesn't mean that European countries have centuries of continued administration, most are a few decades old as a result of revolution or a war.
Europe is a very violent place for politicians, politicians being oversees and untouchable is a very new phenomenon.