IRV produces a direct improvement in the politics in that it promotes coalition-building among minor candidates to defeat better-equipped competition: "vote for me and for this guy too".

That means that instead of everyone running alone and mudslinging each other, which gives voters little narrative to work with(which in turn tends to lead towards the incumbents and partisan votes winning) there's more time and space going towards specific issues and platforms that consensus can be built around.

As a voting system there are certainly better ones in terms of the vote itself, but having experienced the change I now think that the impact on consensus-building is an worthy criterion too.