so you 'win' by finding out that one of your examples of IRV duopoly doesn't actually use IRV
All of my examples were IRV. Ireland uses IRV in their presidential post, and it is two-party dominated (or more like ONE party dominated, except for a single exceptional fluke, when Mary Robinson won). This is especially significant, because Ireland's legislature has multiple viable parties, which should help there be more competetive parties for the post.
The same is true of Australia's house of representatives, since its Senate uses STV, and had something like 6 greens last I checked. But it's house of reps, which uses IRV, is a two party body. Australianpolitics.com says IRV "promotes a two-party system to the detriment of minor parties and independents." In Australian politics, this isn't even questioned, it's just accepted as a fact.
Re: Missing the point
All of my examples were IRV. Ireland uses IRV in their presidential post, and it is two-party dominated (or more like ONE party dominated, except for a single exceptional fluke, when Mary Robinson won). This is especially significant, because Ireland's legislature has multiple viable parties, which should help there be more competetive parties for the post.
The same is true of Australia's house of representatives, since its Senate uses STV, and had something like 6 greens last I checked. But it's house of reps, which uses IRV, is a two party body. Australianpolitics.com says IRV "promotes a two-party system to the detriment of minor parties and independents." In Australian politics, this isn't even questioned, it's just accepted as a fact.