Reply #3: instant runoff sounds good at first

[WillYourVoteBCounted]

but it isn't additive so you can't just add up the votes at the polling places.

IRV incentivizes more complex technology:

It is so complex to count that Scotland adopted computer vote counting in 2007,
It didn't work out well, so computer counting will only be used in their STV/IRV
elections, but not in other elections.

Does IRV help third parties?

Look at San Francisco where there is not 1 single elected third party official,
and they've had IRV since 2004.

We don't know for sure how to audit an IRV election effectively either.

If it worked... might be worth exploring, but in real life usage, it seems to not meet expectations.