I'm not a huge IRV fan or anything but I don't find rangevoting.org to be all that convincing from a US perspective. Most of their references and stats are two decades old or non-existent (e.g. no reference for 80-95% of AUS voters use the NES strategy). Their primary real world evidence is from Australia and Ireland, where independents and third parties currently make up 17% and 47%(!!!) of their parliaments. In the US that number is 0.3% and effectively 0% given how closely Bernie Sanders and Angus King caucus with dems.
Range voting may well be much better, and there are certainly more mathematically sound versions of ranked-choice than IRV, but I think they utterly fail to convince that IRV is just as bad as plurality. They also seem to only take their game theory as far as necessary to reflect Range Voting in the best possible light. For instance, they argue that voters will almost always rank their less preferred of the front-runners last even if they have greater opposition to other candidates, but they don't explore that candidates can and do chase higher rankings among voters that won't rank them #1. It's an obvious and common strategy (candidates were already doing it in my counties first ever RCV election) so I can only assume the reason its not mentioned is that it improves the soundness of RCV in practice.