Australia

I suppose a lot of people who might be roughly characterised as 'right-wing populists' and against status-quo neoliberalism would find the Greens unpalatable, though.

The unpalatable bit for many, particularly young men, is the social progressivism of these parties. I see it time and time again: guys who would be easy Greens voters based on their economic and environmental policies don't take them seriously because their perception is that left-wing politics is primarily focused on issues of gender and sexuality. They don't consider these issues comparatively relevant and get attacked quite viciously online for this position which feeds into this broader alienation problem they are going through due to the shift away from traditional gender roles that would have given their lives meaning. Feeling alienated by the left, these guys drift right towards groups that validate their feelings and welcome them.

I don't necessarily think this is a completely fair perception of The Greens, but the reality is that we live in an age where young people's views are heavily influenced by their social media algorithms. And if those algorithms are constantly feeding them culture war shit , particularly from the US, then it is understandable that they feel this way. Currently, I don't see an organised attempt by left to combat this problem, nor even an admission that we have agency over it. The focus still just seems to be on blaming the right for manipulating these young men.