So before we get into comments like "If the primary reason you fail a criterion is simply because your voting system just says more about a voters actual preferences, thus creating the potential for conflict, it is a weak failure when compared to a voting system that avoids that failure by simply lacking that information."
We should always first, and last say: "I'd take nearly anything over FPTP"
And anyone not doing this is not helping. As someone who has lived through 3 failed voting reforms in my province, I need to make it painfully clear to those not doing this. You are NOT helping.
This isn't something you take several steps towards the right direction. If we take a step and it doesn't work, people are going to stop stepping in that direction and look for other optimization methods. You have to make a large enough step that the loss function actually decreases.
1. the public figures out how it works
2. parties start appearing that arn't getting crushed by other network effects
3. that an understanding of what a strategic vote looks like in the new system is widespread and existing parties start playing the new game.
And since election cycles are often something like... 4 years. You'd need a voting system in place for maybe 20 years before anything positive would start to happen, and that would apply to any voting system put forward.
Like. These systems are for the far flung future of the country. Not... next election.
As to the time frame: remember that Australia has had it for 100+ years. They are dominated (>80%) by 2 parties (even though they have the MAJOR advantage of proportional representation through their parliament). One can say similar things about Ireland, though the domination isn't nearly the same and there are 3 strong parties (they use a variant of IRV called STV).
But remember that neither the math nor the 100+ year experiment has shown that IRV won't collapse into a two party system. You'll find plenty of references through this thread and sources as to why if you search for "approval" (and "monotonicity criterion"). The thing is that the problem is rather complex. We don't just want it so you don't waste your vote, we don't want that to happen with ANY candidate (favorite betrayer criterion). We want other parties to rise up with no disadvantage. We want our voting to be expressive (STAR and score are substantially more expressive that IRV). We want high voter satisfaction efficiency (VSE) -- IRV doesn't do much better than FPTP. We want the system to be resistant to strategic voting. And we want the voting system to be dead simple. Frankly IRV doesn't fit these criteria. Approval fills every category but isn't extremely expressive. Score and STAR are at worst approval voting and at best much more expressive than ordinal (ranked) systems.
But basically everything you're pointing out is well acknowledged and I won't challenge it. More what I'm suggesting is that Hasan and CGP Grey didn't do their research but drove the hype. There is no optimal system for voting, unfortunately, but there are pretty dang good ones. When the experts say cardinal, I'm going with that.
Here's another: https://www.rangevoting.org/TarrIrv.html The most telling argument here, I think, is that a century of IRV hasn't freed Australia from two-party domination.
Another page with simuations: http://zesty.ca/voting/sim/
What voting reforms have been attempted in your province?
As I like to say: "I approve of preferential voting, but I prefer Approval Voting" :-)
With that in mind, I think it is worth looking at which voting reform proposals have been rejected before, and what argument their opponents used. My impression is that cost and complexity tend to be the biggest persuaders, so strategically it makes sense to support a voting system where the ballot marking and counting processes are as familiar as possible.
As a concrete proposal, I suggest a system where people fill in ballots exactly as in FPTP, and the results are counted in exactly the same way, but then the candidate with the least votes gets to reassign their votes to another candidate of their choice, and so on until one candidate receives a majority of votes.
The justification for this is that America did exactly this (not at a national level). As well as that Ireland and Australia are still dominated by two parties, and Australia has had IRV for 100+ years.
Sometimes incremental improvements are actually a step backwards. Specifically when people get over hyped and put too much faith into it.
But I also have to ask, if we already have a better tasting cake and it costs as much as the plain cake, why not take the better one? It isn't more expensive and doesn't take more work. It is just better.