Instant runoff voting is not obviously better than the current system, and in fact it might be worse. Not only does it still have issues with "vote splitting",

Instant runoff voting is not obviously better than the current system, and in fact it might be worse. Not only does it still have issues with "vote splitting", it also has a property called non-monotonicity. This means you can hurt a candidate by ranking them higher, or help a candidate by ranking them lower. I find this to be a fairly dishonorable voting system to implement. If you want voting systems without these issues, you need range voting or condorcet voting.