Eh, I would say that while there isn't a huge amount of alignment between many of Europe's Green parties, they all kinda hate each other for different reasons. The German and UK Greens have gone through a lot of shit over the years for their stances on Israel (way before the conflict), alongside Nuclear energy.
It's often been a long-running joke that the main barrier for the greens in power is themselves. They'd rather attack each other over issues that don't affect the electorate than try to mount a realistic challenge to govern.
Many also don't truly "pay" for things. They leverage debt against their assets, essentially like a fancy credit card that says "I own MegaCorp, you know I'm good for it, just send the bills to this wealth management firm".
So it's not out of the realms of possibility to say that a billionaire is actually spending very little money, ever. What they have is essentially gifts from whoever manages their assets, and that company just skims whatever things "cost".
IMO taxing wealth is what's needed, but it needs to be framed in a way that makes a billionaire want to invest in their country through high taxes. Make it a privilege that is praised, and ostracise those business that excuse themselves from contributing.