As others are saying, there are certainly drawbacks to IRV. I think there are theoretical results showing that all of the mainstream proposals for voting systems are susceptible to strategic voting aka “gaming” your vote, among other issues.

What they aren’t acknowledging is that the situation is even worse with our current system.

My personal preference is approval voting, but I’m down with all sorts of systems that are better than the status quo. I expect that anything that lets you express more of your preferences will increase buy in and participation. Increased participation with preferences closer to people’s true preferences goes hand in hand with increased legitimacy.

We shouldn’t let perfect be the enemy of better.