They barely made it into parliament at all most elections, hovering around 5% in 2002 and 2006 and well below 10% after that until 2021. I think you might be giving them too much credit.
https://en.wikipedia.org/wiki/Alliance_90/The_Greens#Electio...
> Is that actually true?
> If you mean "over the last 20 years", then no, they weren't even a governing party between 2005 and 2021.
You don't have to be in cabinet to influence other parties.