On the contrary, I feel as though a tax like that can only be done at EU level rather than a national level if it wants to have any efficiancy. The ultra-rich are not bound by the same rules of territoriality as the rest of us, and would have no problem moving to another country in the EU if a local tax displeases them.
In fact, this has been a key argument put forward by right-wing politicians against high-wealth tax on a national level for quite some time, that they would flee the country the first chance they get. But by registering it at the EU level, the million/billionaires won't have anywhere to run if they still want to enjoy the benefits of being in the EU :)
Yeah, but the new guy's gonna be cheaper than the one with experience!
I mean, think about the next quarter benefits! Stop searching for stuff like 'reliability' or 'long term'. That doesn't mean anything to the shareholders who'll jump ship the next month.
(It's definitely an hyperbole, but it does raise a good point over hyper short-termism leading to mass layoffs for 'profitability'. The sick days are just the excuse needed to part the employes that will support their hyper toxic management structures from the ones who aren't 'team players')